Method for producing an iron core assembly

ABSTRACT

The magnetic performance, rigidity and mechanical precision of an iron core assembly can be improved. A plurality of plate-shaped core segments are disposed in succession to form a plurality of first and second core members respectively. Edge portions of adjacent core segments of the first and second core members are coupled with each other. The first and second core members are alternately laminated one over another in such a manner that first inter-segment positions each defined between adjacent two first core segments of the first core member are offset from second inter-segment positions each defined between adjacent two second core segments of the second core member in a longitudinal direction of the first and second core members, with those edge portions of the respective first and second core segments which adjoin each other in a laminating direction in which the first and second core members are laminated being overlapped each other. The core segments of the first and second core members are rotated relative to each other through the coupling means so as to form an enclosed or ring-like configuration.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an iron core assembly whichgenerally forms a major or essential part of an electric motor, atransformer and the like, and it also relates to a method of producingsuch an iron core assembly.

[0003] 2. Description of the Related Art

[0004] For example, an iron core assembly of the type mentioned abovehas been used in a conventional electric motor, as disclosed in Japaneseunexamined patent publication (laid-open) No. 9-191588. As shown inFIGS. 58 and 59, such a kind of conventional iron core assemblycomprises a predetermined number of core members 1 stacked or laminatedone over another, each core member 1 being formed of a plurality of coresegments 1 a which are connected together by way of a plurality of thinportions 1 b. In order to improve winding property or efficiency, thestacked core members 1 in their states as shown in FIG. 59 are woundwith wires 2 by means of a winding machine (not shown), and therespective thin portions 1 b thereof are then bent properly to form anannular or ring-shaped core assembly as shown in FIG. 58.

[0005] Since a conventional iron core assembly is constructed in theabove-described manner, when a ring-shaped iron core assembly is formed,every two adjacent core segments 1 a facing each other through a thinportion 1 b, and end faces of each edge portion of core segments 1 alocated on opposite ends of each core member 1, will undesirably producesome rough surface portions and some working size errors during a presspunching process. As a result, every two adjacent core segments 1 a willhave to be brought together with an undesirable clearance of severalmicrometers (μm) to ten-odd micrometers (μm) formed therebetween. Due tothe existence of such kind of clearances, a magnetic resistance willundesirably be increased, resulting in a problem that the magneticperformance of the iron core assembly is deteriorated.

[0006] Further, since-each of the core members 1 forming an iron coreassembly is usually provided on the surface thereof with a skin layer.Such a kind of skin layer is useful in hampering the passing of anmagnetic flux therethrough so as to inhibit a possible eddy currentloss. For this reason, if there is no such kind of skin layer existingon the end faces of punched portions, an undesired eddy current willoccur over the entire area of each end face of each core segment 1 a inthe laminating direction. Because of the occurrence of the eddy current,an undesired iron loss will happen, thus undesirably affecting a desiredmagnetic performance.

[0007] Moreover, on each of the above end faces, since a holding forceintended to act against an external force in parallel with the end facesis relatively weak, the iron core assembly as a whole has only lowrigidity. In particular, if an electric motor is a type in which a forcecaused by magnetism exerts on its iron core assembly, it will bedifficult to ensure a required strength for the motor.

[0008] In addition, since each thin portion 1 b is bent in a manner suchthat a circular configuration is formed as a whole, it is difficult tomechanically ensure high precision for an electric motor. Further, sincebending treatment has to be performed for several times in order to formthe desired circular configuration, some cracks will possibly occur inthe thin portions 1 b, resulting in some problems in which not only themechanical strength is reduced, but also desired magnetic performance isdeteriorated because the cracks will cause an increase in the magneticresistance of a magnetic circuit.

SUMMARY OF THE INVENTION

[0009] In view of the above, the present invention is intended toobviate the above-discussed problems encountered with the conventionaliron core assemblies, and has for its object to provide an improved ironcore assembly of the character described and a method of manufacturethereof which are suitable for mass production and which are capable ofinhibiting a possible increase in the magnetic resistance and a possibleoccurrence of an eddy current so as to obtain improved magneticperformance, thereby ensuring improved rigidity and increased mechanicalprecision for the iron core assembly.

[0010] Bearing the above object in mind, according to a first aspect ofthe present invention, there is provided an iron core assemblycomprising: a first core member having a plurality of plate-shaped firstcore segments disposed in succession; a second core member having aplurality of plate-shaped second core segments disposed in succession;and coupling means for coupling edge portions of adjacent core segmentsof the first and second core members. The first and second core membersare alternately laminated one over another in such a manner that firstinter-segment positions each defined between adjacent two first coresegments of the first core member are offset from second inter-segmentpositions each defined between adjacent two second core segments of thesecond core member in a longitudinal direction of the first and secondcore members, with those edge portions of the respective first andsecond core segments which adjoin each other in a laminating directionin which the first and second core members are laminated beingoverlapped each other. The core segments of the first and second coremembers are rotated relative to each other through the coupling means soas to form an enclosed or ring-like configuration.

[0011] With this arrangement, it is possible to provide an iron coreassembly which is suitable for mas production and can be improved in itsmagnetic performance and mechanical strength.

[0012] In a preferred form of the first aspect of the invention, thecoupling means couples together edge portions of those core segmentswhich adjoin each other in the laminating direction of the first andsecond core members. Thus, it is possible to further improve themagnetic performance and mechanical strength of the iron core assembly.

[0013] In another preferred form of the first aspect of the invention,the coupling means comprises: first concave and convex portionsrespectively formed on a front surface and a back surface of each of thefirst core segments of the first core member at one end edge portionthereof; and second concave and convex portions respectively formed on afront surface and a back surface of each of the second core segments ofthe second core member at the other end edge portion thereof. The firstconcave and convex portions are engageable with the second concave andconvex portions thereby to couple the edge portions of those coresegments which adjoin each other in the laminating direction of thefirst and second core members.

[0014] With this arrangement, it is possible to improve not only themagnetic performance and mechanical strength, but also durability of theiron core assembly against bending operations upon assembling.

[0015] In a further preferred form of the first aspect of the invention,the first concave and convex portions are engageable with the secondconcave and convex portions through clearances. Accordingly, it becomeseasy to rotate coupling portions of the iron core assembly.

[0016] In a yet further preferred form of the first aspect of theinvention, the coupling means comprises: a first hole formed in one endedge portion of each first core segment of the first core member; asecond hole in the other end edge portion of each second core segment ofthe second core member; and a pin member passing through the first andsecond holes in the laminated first and second core segments in thelaminating direction of the first and second core members in such amanner as to allow relative rotation of the first and second coresegments.

[0017] With this arrangement, it is possible not only to improve themagnetic performance and mechanical strength, but also further expediterotation of the iron core assembly upon assemblage thereof, thusensuring improved assembling precision.

[0018] In a still further preferred form of the first aspect of theinvention, each first core segment of the first core member has one endface at least partially formed into a convex arc-shaped configurationand the other end face at least partially formed into a concavearc-shaped configuration, with the convex arc-shaped one end face ofeach first core segment being disposed in abutment with the otherconcave arc-shaped end face of a first core segment adjoining in adirection in which the first core segments are disposed in succession;each second core segment of the second core member has one end face atleast partially formed into a concave arc-shaped configuration and theother end face at least partially formed into a convex arc-shapedconfiguration, with the concave arc-shaped one end face of each secondcore segment being disposed in abutment with the other convex arc-shapedend face of a second core segment adjoining in a direction in which thesecond core segments are disposed in succession; and a center ofrotation of the coupling means which couples the edge portions ofmutually adjacent core segments of the same core member with each otheris disposed at a location which is substantially on a bisector for anangle formed by widthwise centerlines of mutually adjacent two coresegments of the same core member and which is outwardly away from anintersection of the widthwise centerlines. With this arrangement, it ispossible to expedite press-punching operation without deteriorating themagnetic performance of the iron core assembly.

[0019] In a further preferred form of the first aspect of the invention,a center of rotation of the coupling means which rotates each coresegment is disposed at a location which is substantially on a bisectorfor an angle formed by widthwise centerlines of mutually adjacent twocore segments of the same core member and which is outwardly away froman intersection of the widthwise centerlines. Thus, press-punchingoperation can be further improved without affecting the magneticperformance of the iron core assembly.

[0020] In a further preferred form of the first aspect of the invention,the coupling means couples adjacent edge portions of successivelydisposed adjacent core segments of the same first or second core memberwith each other. Accordingly, it is possible to further improve themagnetic performance and mechanical strength of the iron core assembly.

[0021] In a further preferred form of the first aspect of the invention,the coupling means comprises opposing end faces of mutually adjacentedge portions of successively disposed core segments of the first orsecond core members, the opposing end faces being formed into anarticulated configuration. Thus, assembling precision can be furtherimproved, in addition to enhancing the magnetic performanceand-mechanical strength.

[0022] In a further preferred form of the first aspect of the invention,the first core member and the second core member are laminated to form alaminated core unit which has opposite ends formed into complementarystepped configurations in which edge portions of mutually opposed coresegments at the opposite ends of the laminated are superposed each otherin a stepwise fashion in the laminating direction. Thus, it is possibleto improve efficiency in assembling operation.

[0023] In a further preferred form of the first aspect of the invention,the first core member and the second core member are laminated to form alaminated core unit which is formed at opposite ends thereof with aconcave portion and a convex portion which are formed on core segmentsmutually adjoining each other in the laminating direction and which aredetachably engageable with each other. Accordingly, assemblingefficiency can be further improved.

[0024] In a further preferred form of the first aspect of the invention,rotation restricting means is provided on opposing end faces of adjacentedge portions of successively disposed core segments of the first orsecond core member for restricting rotation of the coupling means whenthe laminated first and second core members are formed into the enclosedor ring-like configuration. Accordingly, it becomes possible to positionthe first or second core member in an easy manner, thus furtherimproving the assembling efficiency.

[0025] In a further preferred form of the first aspect of the invention,reverse-rotation restricting means is provided on opposing end faces ofadjacent edge portions of successively disposed core segments of thefirst or second core member for restricting reverse rotation of thecoupling means. Accordingly, wire winding operation can be expedited,thereby improving assembling efficiency.

[0026] According to a second aspect of the present invention, there isprovided an iron core assembly comprising: a first core member having aplurality of first core segment blocks disposed in succession, the firstcore segment blocks each having a plurality of plate-shaped first coresegments laminated one over another; a second core member having aplurality of second core segment blocks disposed in succession, thesecond core segment blocks each having a plurality of plate-shapedsecond core segments laminated one over another; coupling means forcoupling edge portions of adjacent core segment blocks of the first andsecond core members. The first and second core members are alternatelylaminated one over another in such a manner that first inter-blockpositions each defined between adjacent two first core blocks of thefirst core member are offset from second inter-segment positions eachdefined between adjacent two second core blocks of the second coremember in a longitudinal direction of the first and second core members,with those edge portions of the respective first and second core blockswhich adjoin each other in a laminating direction in which the first andsecond core members are laminated being overlapped each other. The coresegment blocks of the first and second core members are rotated relativeto each other through the coupling means so as to form an enclosed orring-like configuration.

[0027] With this arrangement, the magnetic performance and mechanicalstrength of the iron core assembly can be improved, and the number ofcomponent parts of the core assembly can be reduced, thus enhancingproductivity. Beside, when the core segment blocks are to be rotatedtooth by tooth, such rotation becomes easy due to reduced friction.

[0028] In a preferred form of the second aspect of the invention, thecoupling means couples together edge portions of those core segmentblocks which adjoin each other in the laminating direction of the firstand second core members. Thus, the magnetic performance and mechanicalstrength can be further improved.

[0029] In another preferred form of the second aspect of the invention,the coupling means comprises: a first hole formed in one end edgeportion of each first core segment block of the first core member; asecond hole in the other end edge portion of each second core segmentblock of the second core member; and a pin member passing through thefirst and second holes in the laminated first and second core segmentblocks in the laminating direction of the first and second core membersin such a manner as to allow relative rotation of the first and secondcore segment blocks. Accordingly, beside the fact that the magneticperformance and mechanical strength can be improved, it becomes furthereasy to effect rotation of the core segment blocks, thereby enhancingassembling precision.

[0030] In a further preferred form of the second aspect of theinvention, edge portions of successively disposed core segment blocks ofthe first or second core member have opposing end faces one of which isformed into a convex arc-shaped configuration, and the other of which isformed into a concave arc-shaped configuration, a convex arc-shaped endface of one of the mutually adjacent core segment blocks being disposedin abutment with a concave arc-shaped end face of the other of themutually adjacent core segment blocks which is adjacent the one coresegment block of the same core member. Thus, the magnetic performancecan be further improved.

[0031] According to a third aspect of the present invention, there isprovided an iron core assembly comprising: a first laminated core unit;and a second laminated core unit. The first laminated core unitcomprises: a first core member having a plurality of plate-shaped firstcore segments disposed in succession; a second core member having aplurality of plate-shaped second core segments disposed in succession;and first coupling means for coupling edge portions of adjacent coresegments of the first and second core members. The first and second coremembers are alternately laminated one over another in such a manner thatfirst inter-segment positions each defined between adjacent two firstcore segments of the first core member are offset from secondinter-segment positions each defined between adjacent two second coresegments of the second core member in a longitudinal direction of thefirst and second core members, with those edge portions of therespective first and second core segments which adjoin each other in alaminating direction in which the first and second core members arelaminated being overlapped each other. The second laminated core unitcomprises: a third core member having a plurality of plate-shaped thirdcore segments disposed in succession; a fourth core member having aplurality of plate-shaped fourth core segments disposed in succession;and second coupling means for coupling edge portions of adjacent coresegments of the third and fourth core members. The third and fourth coremembers are alternately laminated one over another in such a manner thatthird inter-segment positions each defined between adjacent two thirdcore segments of the third core member are offset from fourthinter-segment positions each defined between adjacent two fourth coresegments of the fourth core member in a longitudinal direction of thethird and fourth core members, with those edge portions of therespective third and fourth core segments which adjoin each other in alaminating direction in which the third and fourth core members arelaminated being overlapped each other. The core segments of the firstand second core units are rotated relative to each other through thefirst and second coupling means so as to form an enclosed or ring-likeconfiguration.

[0032] With the above arrangement, the entire laminated core can bedivided into a plurality of core units each having such a size assuitable for assembling operation, thus improving assembling efficiency.

[0033] According to a fourth second aspect of the present invention,there is provided an iron core assembly comprising: a first laminatedcore unit which comprises: a first core member having a plurality ofplate-shaped first core segments disposed in succession; a second coremember having a plurality of plate-shaped second core segments disposedin succession; and coupling means for coupling edge portions of adjacentcore segments of the first and second core members. The first and secondcore members are alternately laminated one over another in such a mannerthat first inter-segment positions each defined between adjacent twofirst core segments of the first core member are offset from secondinter-segment positions each defined between adjacent two second coresegments of the second core member in a longitudinal direction of thefirst and second core members, with those edge portions of therespective first and second core segments which adjoin each other in alaminating direction in which the first and second core members arelaminated being overlapped each other. A second laminated core unit hasa plurality of plate-shaped core segments laminated one over another.The core segments of the first laminated core unit are rotated relativeto each other through the coupling means thereby to combine the firstand second core units so as to form an enclosed or ring-likeconfiguration. Thus, just like the above, the entire laminated core canbe divided into a plurality of core units each having a size suitablefor assembling operation, and hence assembling efficiency can beimproved.

[0034] According to a fifth aspect of the present invention, there isprovided a method for producing an iron core assembly, the methodcomprising the steps of: disposing a plurality of plate-shaped firstcore segments in succession to form first core members; disposing aplurality of plate-shaped second core segments in succession to formsecond core members; alternately laminating first and second coremembers one over another in such a manner that first inter-segmentpositions each defined between adjacent two first core segments of eachfirst core member are offset from second inter-segment positions eachdefined between adjacent two second core segments of each second coremember in a longitudinal direction of the first and second core members,with those edge portions of the respective first and second coresegments which adjoin each other in a laminating direction in which thefirst and second core members are laminated being overlapped each other;coupling edge portions of adjacent core segments of the first and secondcore members through coupling means; and rotating the core segments ofthe first and second core members relative to each other through thecoupling means so as to form an enclosed or ring-like configuration.Thus, an improved iron core assembly can be obtained which has improvedmagnetic performance and mechanical strength.

[0035] According to a sixth aspect of the present invention, there isprovided a method for producing an iron core assembly, the methodcomprising the steps of: laminating a plurality of plate-shaped firstcore segments one over another to form first core segment blocks;laminating a plurality of plate-shaped second core segments one overanother to form second core segment blocks; successively disposing thefirst core segment blocks in a line to provide first core members;successively disposing the second core segment blocks in a line toprovide second core members; alternately laminating first and secondcore members one over another in a direction in which the first andsecond core segments are laminated, in such a manner that firstinter-block positions each defined between adjacent two first coresegment blocks of each first core member are offset from secondinter-block positions each defined between adjacent two second coresegment blocks of each second core member in a longitudinal direction ofthe first and second core members, with those edge portions of therespective first and second core segments which adjoin each other in adirection in which the first and second core members are laminated beingoverlapped each other; coupling edge portions of respective adjacentcore segment blocks of the first and second core members throughcoupling means; and rotating the core segment blocks of the first andsecond core members relative to each other through the coupling means soas to form an enclosed or ring-like configuration.

[0036] With this arrangement, as described above, the magneticperformance and mechanical strength of the iron core assembly can beimproved, and the number of component parts of the core assembly can bereduced for improved productivity. Moreover, when the core segmentblocks are to be rotated tooth by tooth, it becomes easy to effect suchrotation due to reduced friction.

[0037] The above and other objects, features and advantages of thepresent invention will more readily apparent from the following detaileddescription of preferred embodiments of the invention when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038]FIG. 1 is a plan view schematically illustrating the structure ofan iron core assembly constructed according to a first embodiment of thepresent invention.

[0039]FIG. 2 is a plan view schematically illustrating a process forforming core members shown in FIG. 1, by means of press punching.

[0040]FIG. 3 is a cross sectional view schematically illustrating thestructure of coupling portions of the core members obtained in theprocess shown in FIG. 2.

[0041]FIG. 4 is a plan view schematically illustrating a state in whichthe core members obtained in the process shown in FIG. 2 are laminated.

[0042]FIG. 5 is a cross sectional view schematically illustrating thestructure of edge portions of the core segments laminated in a manner asshown in FIG. 2.

[0043]FIG. 6 is a view similar to FIG. 5, but illustrating a modifiedstructure of edge portions of the core segments.

[0044]FIG. 7 is a view similar to FIG. 4, but illustrating a modifiedform of core members.

[0045]FIG. 8 is a view similar to FIG. 7, but illustrating a differentoperating state of the core members.

[0046]FIG. 9 is an enlarged plan view of adjacent core segmentsaccording to the first embodiment, showing a connected state of edgeportions thereof.

[0047]FIG. 10 is a view similar to FIG. 9, but illustrating a differentoperating state of the core segments.

[0048]FIG. 11 is a plan view illustrating a process for forming coremembers for an iron core assembly by way of press punching, according toa second embodiment of the present invention.

[0049]FIG. 12 is a plan view illustrating the structure of a first coremember made in the process of FIG. 11.

[0050]FIG. 13 is a plan view illustrating the structure of a second coremember made in the process of FIG. 10.

[0051]FIG. 14 is a plan view illustrating that the first and second coremembers shown in FIG. 11 and FIG. 12 are laminated alternately.

[0052]FIG. 15 is a perspective view of the laminated first and secondcore members shown in FIG. 14.

[0053]FIG. 16 is a plan view illustrating a part of the structure of aniron core assembly constructed according to the second embodiment.

[0054]FIG. 17 is a developed perspective view schematically illustratingthe structure of essential portions of an iron core assembly constructedaccording to a third embodiment of the present invention.

[0055]FIG. 18 is an enlarged plan view schematically illustrating amodified form of an iron core assembly according to the thirdembodiment.

[0056]FIG. 19 is a view similar to FIG. 18, but illustrating a differentoperating state.

[0057] FIGS. 20(A) and 20(B) are cross sectional views showing thestructure of an iron core assembly constructed according to a fourthembodiment of the present invention, wherein FIG. 20(A) illustrates thatedge portions of core segments at opposite ends of a laminated core unitare opposing to each other, and FIG. 20(B) illustrates that edgeportions of core segments at opposite ends of a laminated core unit areplaced in abutting engagement with each other.

[0058] FIGS. 21(A) and 21(B) are views similar to FIGS. 20(A) and 20(B),respectively, but showing a modified structure of an iron core assemblyconstructed according to a fourth embodiment of the present invention.

[0059] FIGS. 22(A) through 22(D) are plan views illustrating a methodfor assembling essential portions of an iron core assembly according toa fifth embodiment of the present invention.

[0060] FIGS. 23(A) through 23(D) are cross sectional views correspondingto FIGS. 22(A) through 22(D), respectively, illustrating the sameassembling method.

[0061]FIG. 24 is a front elevation view illustrating the structure of aniron core assembly constructed according to a sixth embodiment of thepresent invention.

[0062]FIG. 25 is a plan view illustrating a material from which coremembers shown in FIG. 24 are formed by means of press punching.

[0063]FIG. 26 is a plan view of divided laminated core units of an ironcore assembly according to a seventh embodiment of the presentinvention.

[0064]FIG. 27 is a plan view schematically illustrating the structure ofan core iron core assembly completely constructed from the laminatedcore units of FIG. 26.

[0065]FIG. 28 is a plan view schematically illustrating the structure ofan iron core assembly according to an eighth embodiment of the presentinvention.

[0066]FIG. 29 is a plan view schematically illustrating the structure ofcore members shown in FIG. 28.

[0067]FIG. 30 is an enlarged plan view of essential portions of a coremember of an iron core assembly according to the eighth embodiment, butshowing a structure different from that shown in FIG. 29.

[0068]FIG. 31 is a plan view schematically illustrating a condition inwhich the core member shown in FIG. 30 has been formed into aring-shaped configuration.

[0069]FIG. 32 is a view similar to FIG. 30, but illustrating a modifiedform of core member.

[0070]FIG. 33 is a plan view illustrating a condition where the coremember shown in FIG. 32 has been formed into a ring-shapedconfiguration.

[0071]FIG. 34 is a view similar to FIG. 32, but illustrating anothermodified form of core member.

[0072]FIG. 35 is a plan view illustrating a condition where the coremember shown in FIG. 34 has been formed into a ring-shapedconfiguration.

[0073]FIG. 36 is a developed perspective view schematically illustratingthe structure of an iron core assembly constructed according to ninthembodiment of the present invention.

[0074]FIG. 37 is a plan view schematically illustrating the structure ofcore members of an iron core assembly according to the ninth embodiment,but having a different structure from that shown in FIG. 36.

[0075]FIG. 38 is a plan view schematically illustrating an iron coreassembly in which a plurality of core members shown in FIG. 37 have beenformed into a ring-shaped configuration.

[0076]FIG. 39 is a plan view of laminated core units before assemblageof an iron core assembly according to a tenth embodiment of the presentinvention.

[0077]FIG. 40 is a plan view illustrating an iron core assemblyconstructed from the laminated core units of FIG. 39.

[0078]FIG. 41 is a front elevation view schematically illustrating thestructure of an iron core assembly for a zero-phase-sequence currenttransformer according to an eleventh embodiment of the presentinvention.

[0079] FIGS. 42(A) and 42(B) are plan views illustrating process stepsfor a method of assembling core members of the iron core assembly shownin FIG. 41.

[0080]FIG. 43 is an operation diagram illustrating steps for bending acore member through rotation of coupling means.

[0081] FIGS. 44(A) through 44(D) are view illustrating the principle ofthe present invention.

[0082]FIG. 45 is a front elevation view schematically illustrating thestructure of an iron core assembly for an electric motor according to atwelfth embodiment of the present invention.

[0083] FIGS. 46(A) through 46(C) are plan views illustrating processsteps for a method of assembling core members of the iron core assemblyshown in FIG. 41.

[0084] FIGS. 47(A) and 47(B) are plan views illustrating the structureof essential portions of a core member shown in FIG. 46, butrespectively showing different operating conditions thereof.

[0085] FIGS. 48(A) and 48(B) are plan views respectively illustratingessential portions of adjacent core segments with different couplingsections.

[0086] FIGS. 49(A) and 49(B) are perspective views of a first and asecond core segment block, respectively, illustrating a core pressingprocess according to a thirteenth embodiment of the present invention.

[0087]FIG. 50 is a perspective view illustrating an axially couplingprocess for axially coupling a plurality of core segment blocks stackedin a row.

[0088]FIG. 51 is a developed perspective view of three-teeth coresegment blocks, illustrating a stacking and arraying process.

[0089]FIG. 52 is a developed perspective view of three-teeth coresegment blocks, illustrating a temporal coupling process.

[0090]FIG. 53 is a developed perspective view of three-teeth coresegment blocks, illustrating an insulation piece assembling process.

[0091]FIG. 54 is a perspective view of three-teeth core segment blocks,illustrating a wire-winding process.

[0092]FIG. 55 is a perspective view, illustrating a three-teeth blockingand fixing process.

[0093]FIG. 56 is a development view of an iron core assembly,illustrating a circularly coupling process.

[0094]FIG. 57 is a perspective view of the iron core assembly,illustrating a wiring, varnishing, and shrinkage fitting process.

[0095]FIG. 58 is a plan view schematically illustrating the structure ofa conventional iron core assembly for an electric motor.

[0096]FIG. 59 is a plan view schematically illustrating the structure ofa core member shown in FIG. 58.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0097] In the following, several presently preferred embodiments of thepresent invention will be described while referring to the accompanyingdrawings.

[0098] Embodiment 1

[0099] Referring to the drawings and first to FIG. 1, there isschematically illustrated the structure of an iron core assemblyconstructed according to a first embodiment of the present invention.FIG. 2 schematically shows in a plan view a process for forming coremembers shown in FIG. 1, by means of press punching. FIG. 3schematically shows in cross section the structure of the couplingportions of the core members obtained in the process of FIG. 2. FIG. 4schematically shows in a plan view a condition in which the core membersobtained in the process of FIG. 2 are connected together. FIG. 5schematically shows in cross section the structure of edge portions ofthe core segments stacked or laminated in a manner as shown in FIG. 2.

[0100] Referring to the above identified figures, a plurality of planaror flat generally T-shaped core segments 3 are each made of aplate-shaped magnetic material. Every two adjacent core segments 3 areconnected with each other by virtue of a concave portion 3 a and aconvex portion 3 b which are formed on the front and back surfaces ofadjacent two core segments 3 to cooperate with each so as to serve as acoupling means in the form of a joint. Each flat T-shaped core member 3has an elongated magnetic pole piece and a head or cross pieceintegrally formed therewith. The cross piece of each flat T-shaped coremember 3 has one end face 3 c formed into a convex arc-shapedconfiguration, which is concentric with the concave portion 3 a and theconvex portion 3 b. The cross piece of each flat T-shaped core member 3has the other end face 3 d formed into a concave arc-shapedconfiguration complementary in shape to the convex arc-shaped end face 3c so as to be in fitting engagement therewith. As shown in FIG. 2, afirst core member 4 comprises a plurality of core segments 3 which arecontinuously and serially disposed in a line with the respective endfaces 3 c, 3 d of every two adjacent ones being in contact with eachother. Similarly, a second core member 5 comprises a plurality of coresegments 3 which are continuously and serially disposed in a line withthe respective end faces 3 c, 3 d of every two adjacent ones being incontact with each other, but the direction of each core segment 3 of thesecond core member 5 is opposite to that of each core segment 3 of thefirst core member 4, that is to say, each core segment 3 of the secondcore member 5 is disposed in a mirror image relation with respect tothat of the first core member 4. More specifically, the convexarc-shaped end face 3 c and the concave arc-shaped end face 3 d of eachcore segment 3 of the second core member 5 are disposed just opposite tothose of each core segment 3 of the first core member 4. Each coresegment 3 of the first core member 4 is formed on its opposite surfacesat one end of its cross piece with a first connection means in the formof a concave portion 3 a and a convex portion 3 b, respectively, andlikewise each core segment 3 of the second core member 5 is formed onits opposite surfaces at the other end of its cross piece with a secondconnection means in the form of a concave portion 3 a and a convexportion 3 b, respectively.

[0101] As shown in FIGS. 3, 4 and 5, a plurality of first core members 4and a plurality of second core members 5 are alternately disposed inparallel with respect to one another and stacked or laminated-one overanother. The first and second core members 4, 5 are disposed in such amanner that interstices or inter-segment spaces or gaps between everytwo adjacent core segments 3 of the first core members 4 are displacedfrom those between every two adjacent core segments 3 of the second coremembers 5 in a longitudinal direction or along the length thereof withone end of the cross piece of each first core segment 3 being overlappedon the other end of the cross piece of an associated second core segment3 which is disposed adjacent the first core segment 3 in a stackingdirection in which the first and second core members 4, 5 are stacked orlaminated. The concave portion 3 a and the convex portion 3 b of eachfirst core segment 3 at one end of its cross piece are placed intofitting engagement with the convex portion 3 b and the concave portion 3a, respectively, of an associated second core segment 3 at the other endof its cross piece which is disposed adjacent the first core segment 3in the stacking direction, thus connecting the mutually adjacent firstand second core segments 3 together in a rotatable or turnable mannerwith respect to each other. As illustrated in FIG. 1, a wire 6 is woundaround the magnetic pole tooth or piece 3 f (see FIG. 1) of each coresegment 3. The respective core segments 3 of the first and second coremembers 4, 5 thus rotatably connected through engagement of the concaveand convex portions 3 a, 3 b are then rotated or turned around theengaged concave and convex portions to form an annular iron coreassembly, generally designated at a reference numeral 7. Here, note thatin FIG. 1, the opposite ends of the laminated first and second coremembers 4, 5 are simply abutted against each other to be connectedtogether, and for this reason, any connection means such as convexes andconcaves are omitted or unprovided there.

[0102] In the following, a detailed description will be given in orderto explain a method of producing an iron core assembly in accordancewith the first embodiment of the present invention.

[0103] At first, in a position indicated at an arrow T in FIG. 2, convexand concave portions for pressure engagement are press-punched on thefront and back surfaces of a core member at three locations per coresegment. In this first step, as depicted in FIG. 3, the concave andconvex portions 3 a, 3 b are formed on the opposite end edges of eachcore segment 3, and two concave and convex portions for connection ofstacked or laminated core members 4, 5 are also formed at the center ofeach core segment 3, i.e., at the widthwise center of the leg and thelongitudinal center of the cross piece. Then, in a position indicated atarrow A in FIG. 2, as a second step for forming the first core members4, a plurality of hatched portions in the figure are press-punched to beremoved, so as to form end faces 3 c and 3 d as well as theirsurrounding portions. Then, in a position shown by arrow B in thefigure, as a second step for forming the second core members 5 whichhave concave and convex portions formed at the process step T, aplurality of hatched portions in the figure are press-punched to beremoved, so as to form end faces 3 c and 3 d and their surroundingportions.

[0104] Subsequently, in the position indicated at arrow C, in thoseportions of each core segment which have the opposite end faces 3 c, 3 dformed at the process step A and the opposite end faces 3 c, 3 d formedat the process step B, hatched portions shown in FIG. 1 arepress-punched in succession in an alternate manner to provide the firstand second core members 4, 5, which are then stacked in succession in amold.

[0105] In a position indicated arrow S, three through holes per coresegment are formed therein by way of press-punching at the samelocations as the concave and convex portions formed at the process stepT. In this manner, three through holes 3 e are formed in each of thecore segments 3 which will be the uppermost ones when the first andsecond core members 4, 5 have been stacked. Thereafter, in a positionindicated at an arrow B, as a second step for processing a third coremember 51, hatched portions-shown in FIG. 1 in those portions of eachcore segment 3 in which the through holes 3 e have been formed at theprocess step S are press-punched to provide opposite end faces 3 c, 3 dand their surrounding portions. Finally, in the position indicated at anarrow C, hatched portions shown in FIG. 1 in those portions of each coresegment 3 in which the opposite end faces 3 c, 3 d have been formed atthe process step B are press-punched to provide a third core member 51,which is then stacked on the laminated first and second core members asan uppermost layer in a mold. For example, the thickness of eachplate-shaped core segment is 0.5 mm and the number of core segmentsstacked is 150 sheets.

[0106] In FIG. 2, the core segments 3 at the opposite ends of the firstcore member 4 or the second core member 5 are not aligned in part withthe intermediate core segments 3 at their edge portions. This is toexpedite abutting engagement or connection of the end core segments 3,which constitute the ends of the stacked or laminated first and secondcore members 4, 5. This is true of the following embodiments.

[0107] The first and second core members 4, 5 are stacked or laminatedalternately within a mold with the third core member 51 being disposedthereon as the uppermost layer. During stacking, each pair of twomutually facing concave portion 3 a and convex portion 3 b and each pairof two mutually facing through holes 3 e and convex portion 3 b arecaused to be engaged with each other in a stacking or laminatingdirection of core segments 3, thereby forming an integrally connectedarrangement, as shown in FIG. 4. Further, the magnetic pole tooth or leg3 f of each core segment 3 of the mutually laminated core members 4, 5and 51 is wound by a wire 6 (not shown) in a condition shown in FIG. 4.Subsequently, by properly rotating or turning the adjacent core segments3 relative to each other about mutually engaged concave and convexportions 3 a, 3 b as well as through holes 3 e and convex portions 3 b,an annular or ring-shaped siron core assembly 7 is completed.

[0108] As described above, according to the first embodiment, sinceevery two adjacent edge portions are stacked or laminated together in amanner such that they are overlapped one over another in the laminatingdirection of the core segments 3, the surface area on each connection(overlapped edge portions) between two adjacent core segments 3 can beincreased, thereby making it possible to inhibit an increase in themagnetic resistance thereof and thus improving the magnetic performanceof the iron core assembly. Further, since the end faces 3 c and 3 d ofthe punched core segments 3 are alternately diverged or displaced to anextent corresponding to an overlapped area thereof so as to be decoupledin the laminating direction (i.e., the end faces 3 c, 3 d of therespective core segments 3 being made discontinuous), it is allowedto-reduce an area on which the end faces 3 c and 3 d are existing in thesame plane. As a result, it is possible to inhibit the occurrence ofeddy current, thereby reducing an iron loss and hence improving themagnetic performance of the iron core assembly.

[0109] Further, a force acting in the laminating direction on the ironcore assembly is supported by the alternately overlapped portions of therespective core segments 3, so that the rigidity of the iron coreassembly 7 and hence the mechanical strength thereof can be improved.Also, as shown in FIG. 5, the plurality of first and second core members4, 5 may be alternately overlapped one over another so that a magneticpath passing through the first and second core members 4, 5 is formed inthe laminating direction of the first and second core members 4, 5 inthe overlapped portions of the edge portions of adjacent core segments 3disposed in the laminating direction, thereby improving the magneticperformance of the core assembly.

[0110] As illustrated in FIG. 6, a plurality (e.g., 2-10, and 2 in theillustrated embodiment) of first or second core members 4, 5 may bestacked or laminated to form a group of laminated core members. In thiscase, a plurality of groups of laminated first core members 4 and aplurality of groups of laminated second core members 5 are alternatelylaminated together with one group of the first core members 4 lying overanother group of the second core members 5. With such an arrangement,the greater the number of core members forming one group, frictionbetween adjacent core segments 3 can be reduced when the respective coresegments are rotated or turned about their associated connectors (e.g.,the engaged concave and convex portions). In addition, when thelaminated first and second core members 4, 5 are shaped into an enclosedor ring-like configuration with their opposite ends being connected witheach other, the greater the number of laminated first core members orsecond core members for one group, it becomes the easier to place theends of the first and second core members into fitting engagement withrespect to each other, improving the productivity of the core assembly.

[0111] In addition, by properly rotating the engaging sections ofadjacent core segments including a concave portion 3 a and a convexportion 3 b relative to each other, the mutually laminated first andsecond core members 4, 5 may be bent to form a generally ring-shapedconfiguration. In this way, it is allowed to perform such bending forseveral times without causing any deterioration in its mechanicalstrength. Moreover, since the end faces 3 c, 3 d of each plate-shapedcore segment 3 are each formed into an arc-shaped configuration in aconcentric relation with respect to both the associated concave portion3 a and convex portion 3 b, it is easy to rotate or turn the mutuallyengaged concave and convex portions and hence the adjacent core segmentsrelative to each other, making it possible to improve an operationalefficiency when winding a wire to form a desired coil thereon.

[0112] Nevertheless, though not shown in the drawings, if an appropriateclearance is properly formed in the engaging sections comprising aconcave portion 3 a and a convex portion 3 b, such a clearance may beeffectively used to absorb an accumulated error which would otherwisepossibly occur during the above-mentioned press punching processing.Further, such a kind of clearance is also useful in expediting relativerotation between engaged concave and convex portions 3 a, 3 b.

[0113] Further, as shown in FIG. 7, the concave portion 3 a on each coresegment 3 may be elongated in the longitudinal direction of the first orsecond core member 4, 5, it is possible for each convex portion 3 b tomove a little along and within the elongated said concave portion 3 a inits longitudinal direction. In this manner, as seen from FIG. 8, it ispossible to further enlarge an interval between every two adjacent coresegments 3, thus further improving an efficiency in the operation ofwinding a wire to form a coil. Here, note that a chain dot line in FIG.7 or 8 shows that a core segment is permitted to move along the chaindot line within the elongated length of a concave portion 3 a.

[0114] Further, as illustrated in FIG. 9, the end faces 3 c, 3 d of acore segment 3 may be formed into some polygonal shapes, so that whenadjacent core segments 3 of first and second core members 4, 5 areproperly rotated relative to each other about mutually engaged concaveand convex portions 3 a, 3 b so as to bend the first and second coremembers 4, 5, corners of adjacent end faces 3 c, 3 d may be abuttinglyengaged with each other to be deformed to some extent, as shown in FIG.10, so that they are firmly fixed together, thereby increasing therigidity of the iron core assembly 7 and hence improving the mechanicalstrength thereof.

[0115] Embodiment 2

[0116]FIGS. 11 through 16 relate to a second embodiment of the presentinvention. FIG. 11 illustrate a process for forming several types ofcore members for an iron core assembly by way of press punching,according to the second embodiment. FIG. 12 is a plan view showing thestructure of first core members fabricated in a process of FIG. 11. FIG.13 is a plan view showing the structure of second core membersfabricated in a process of FIG. 11. FIGS. 14 and 15 are a plan view anda perspective view, respectively, showing that the first core membersand the second core members may be stacked or laminated in an alternatemanner. In FIG. 15, three core segments 8 from the right-hand end of anuppermost layer are removed. FIG. 16 is a plan view showing part of thestructure of an iron core assembly fabricated according to the secondembodiment.

[0117] In these figures, a reference numeral 8 represents a plurality ofplate-shaped core segments. Like the previously mentioned firstembodiment, each core segment 8 comprises a tooth or leg and a head orcross piece, but in this second embodiment, the cross piece has one endthereof formed into a generally circular-shaped concave portion 8 a andthe other end thereof formed into a generally circular-shaped convexportion 8 b which is complementary in shape to its concave portion 8 aand engageable with a similar concave portion 8 a of an adjacent coresegment 8. These concave and convex portions 8 a and 8 b, once engagedtogether, may be separated from each other only in the laminatingdirection thereby forming an articulated structure serving as a couplingmeans or mechanism. As shown in FIG. 12, a first core member 9 comprisesa plurality of core segments 8 which are articulately connected with oneanother side by side through engagements between adjacent concaveportions 8 a and convex portions 8 b. Similarly, as shown in FIG. 13, asecond core member 10 comprises a plurality of core segments 8 which arearticulately connected with each other side by side through engagementsbetween adjacent concave portions 8 a and convex portions 8 b which areall disposed in just an opposite or reversed direction to those of thefirst core member 9. Specifically, a core segment 8 of the first coremember 9 has a convex portion 8 b formed at one end thereof (e.g., atthe left-hand end in FIG. 12) and a concave portion 8 a formed at theother end thereof (e.g., at the right-hand end in FIG. 12), whereas acore segment 8 of the second core member 10 has a concave portion 8 aformed at one end thereof (e.g., at the left-hand end in FIG. 13) and aconvex portion 8 b formed at the other end thereof (e.g., at theright-hand end in FIG. 13).

[0118] As shown in FIGS. 14 and 15, the first and second core members 9,10 are laminated together in an alternate manner and disposed such thatrespective inter-segment positions or clearances (i.e., intersticesbetween mutually confronting or engaging concave and convex portions 8a, 8 b of adjacent core segments 8) of the first core member 9 aredisplaced from those of the second core member 10 in the longitudinaldirection with adjacent edge portions of those core segments whichadjoin each other in the laminating direction being overlapped oneanother. The first and second core members 9, 10 thus laminated arearticulately bended about the concave-convex engagements 8 a, 8 b whichare rotated or turned relative to each other, thereby forming an annularor ring-shaped iron core assembly.

[0119] In the following, a detailed description will be given to explainhow to produce an iron core assembly in accordance with the secondembodiment of the present invention.

[0120] At first, in a position indicated at arrow T in FIG. 11, as afirst step for forming a first and a second core member 9, 10, on thefront and back surfaces of an iron sheet or plate-shaped material, thereare formed, by way of press punching, two concave and convex portionsper core segment 8, which are adapted to be press fitted or engaged withcorresponding ones in an adjacent core segment 8 at a later stage. Inthis first step, two concave and convex portions for connection ofadjacent core segments 8 of first and second core members 9, 10 to belaminated as shown in FIG. 15 are thus formed in a portion correspondingto the center of each core segment 8, i.e., one in the longitudinalcenter of the head or cross piece and the other in the widthwise centerof the magnetic pole tooth or leg. Then, in a position indicated atarrow A in FIG. 11, as a second step for forming the first core member9, a plurality of cuts 12 are provided to define the contours of theconcave portions 8 a and the convex portions 8 b. Subsequently, in aposition indicated at arrow C in FIG. 11, as a third step, a pluralityof hatched parts surrounding the cut portions in the figure arepress-punched to be removed, so as to form peripheries of the respectiveconcave portions 8 a and convex portions 8 b. Further, in the positionindicated at arrow B in FIG. 11, as a second step for forming the secondcore member 10, similar to the step indicated at arrow A, a plurality ofcuts 13 are provided to those portions on which concave and convexportions 8 a, 8 b have been formed at the step indicated at arrow T,thus defining the contours of the concave portions 8 a and the convexportions 8 b. Then, in a position indicated at arrow D in FIG. 11, as athird step, a plurality of hatched portions surrounding the cut parts inthe figure are press-punched to be removed, so as to form peripheries ofthe respective concave portions 8 a and convex portions 8 b.

[0121] Thereafter, in a position indicated at arrow E in FIG. 11,portions including the concave portions 8 a and the convex portions 8 bformed in the position indicated at arrow C and portions including theconcave portions 8 a and the convex portions 8 b formed in the positionindicated at arrow D are successively processed in an alternate mannersuch that the hatched portions shown in the figure are alternatelypress-punched so as to be removed, thereby forming the first core member9 and the second core member 10. The first core members 9 and the secondcore members 10 thus formed are then placed in a mold and successivelylaminated therein.

[0122] Moreover, in a position indicated at arrow S, two through-holesper core segment are press-punched through the plate-shaped material atthe same locations as those of concave and convex portions formed at thestep indicated at arrow T, thereby forming two through-holes per coresegment 8 in a third core member 52 (see FIG. 15) which constitutes atop or uppermost layer of the laminated first and second core members 9,10. Then, in the position indicated at arrow B, as a second step forforming the third core member 52, a plurality of cuts 13 are provided tothose portions on which concave and convex portions 8 a, 8 b have beenformed at the step indicated at arrow S, thus defining the contours ofthe concave and convex portions 8 a, 8 b. Then, in a position indicatedat arrow D in FIG. 11, as a third step, a plurality of hatched portionssurrounding the cut parts in the figure are press-punched to be removed,so as to form peripheries of the respective concave portions 8 a andconvex portions 8 b. Thereafter, in a position indicated at arrow E inFIG. 11, portions including the concave portions 8 a and the convexportions 8 b formed in the position indicated at arrow D aresuccessively processed so that the hatched portions shown in the figureare press-punched so as to be removed, thereby forming the third coremember 52, which is then placed in the mold and stacked on the laminatedfirst and second core members 9, 10 as the top or uppermost layer.

[0123] In the mold, the concave and convex portions confronting witheach other in the laminating direction of the respective core segments 8are press-fitted or engaged with each other and caulked for preventingthem from being slipped off, thus providing an integral unit.Subsequently, under the condition shown in FIG. 15, the magnetic poletooth 8 f of each core segment 8 is wound with a wire (not shown) so asto form a coil thereon. After that, as shown in FIG. 16, the coremembers are bent about the engaged concave and convex portions 8 a, 8 bthrough relative rotation thereof so as to form a ring-shapedconfiguration, thus completing the iron core assembly 11.

[0124] In this way, according to the second embodiment of the presentinvention, each core segment 8 are formed at its opposite ends with aconcave portion 8 a and a convex portion 8 b, which are rotatablyengaged with each other so as to rotatably connect adjacent coresegments 8 with each other in an articulated manner. By properlyrotating the mutually engaged concave portions 8 a and the convexportions 8 b relative to each other, adjacent core members 9 and 10 canbe bent properly so as to form a ring-shaped iron core assembly, whichis of course easily rotatable and at the same time permits an improvedprecision in assembling an iron core of this kind.

[0125] Embodiment 3.

[0126]FIG. 17 is a developed perspective view schematically illustratingthe structure of major or essential portions of an iron core assemblyproduced according to a third embodiment of the present invention. FIG.18 is a plan view schematically showing the essential portions of aniron core assembly according to a modified form of the embodiment ofFIG. 17. FIG. 19 is also a view similar to FIG. 18, but showing adifferent state of the essential portions of the modified iron coreassembly of FIG. 17.

[0127] In the figures identified above, a reference numeral 14represents a plurality of T-shaped planar core segments made of amagnetic material. Each T-shaped core segment comprises a magnetic poletooth or leg and a head or cross piece. On one end of the cross piece ofeach core segment 14 is formed a through hole 14 a and an end face 14 bhaving a circular arc shape with the through hole 14 a as its arccenter. The other end of the cross piece of each core segment 14 isformed into a circular arc-shaped concave end face 14 c which iscomplementary in shape to and engageable with a circular arc-shapedconvex end face 14 b of an adjacent core segment 14. A first core memberor layer 15 comprises a plurality of core segments 14 which aresuccessively disposed in a line side by side with one end face 14 b of acore segment 14 confronting with the other end face 14 c of anotheradjacent core segment 14 with an appropriate clearance formedtherebetween. Similarly, a second core member or layer 16 comprises aplurality of core segments 14 which are successively disposed in a lineside by side in a different manner from the first core member 15, i.e.,in just an opposite or reversed relation with the first core member 15in the longitudinal direction. Each core segment 14 of the first coremember 15 has a through hole 14 a formed through one end edge portionthereof, i.e., at one end of its cross piece, whereas each core segment14 of the second core member 16 has a through hole 14 a formed throughthe other end edge portion thereof, i.e., at the other end of its crosspiece.

[0128] As seen from FIG. 17, a plurality of first core members 15 and aplurality of second core members 16 are alternately laminated one overanother with inter-segment positions of the first core members 15 (i.e.,clearances between mutually confronting end faces 14 b, 14 c of adjacentcore segments 14) being displaced from those of the second core members16 in the longitudinal direction, so that end or edge portions of thecross pieces of respective core segments 14 adjoining in the laminatingdirection thereof are overlapped one over another. A plurality of pinmembers 17 are each inserted into a plurality of aligned through holes14 a in laminated respective core segments 14 to rotatably orarticulately connect together the laminated core segments (i.e.,alternately laminated first and second core members 15, 16) adjoiningeach other in the laminating direction. Such pin members 17 can beprevented from sliding off by caulking on opposite ends thereof. In thisregard, note that each of the pin members 17 may comprise a bolt-and-nutcombination. The through holes 14 a in the core segments 14 of the firstand second core members 15, 16 and the pin members 17 togetherconstitute a coupling means or mechanism. The core segments 14 areproperly rotated at the pin members 17, so that the first core members15 and the second core members 16 may be bent into a ring-shapedconfiguration, thereby providing a desired iron core assembly, and atthe same time permitting an improvement in precision when assembling aniron core assembly of this kind.

[0129] However, as shown in FIGS. 18 and 19, if the inner surface ofeach through hole 14 a and the outer surface of each pin member 17 areformed into polygonal shapes, when the two kinds of core members 15 and16 are bent into a ring-shaped configuration, it is possible to furtherimprove the rigidity of the iron core assembly and its mechanicalstrength by fixing the polygonal outer surface of each pin member 17into the polygonal inner surface of each through hole 12 a, as shown inFIG. 19.

[0130] Embodiment 4

[0131] FIGS. 20(A) and 20(B) show the structure of essential portions ofan iron core assembly constructed according to a fourth embodiment ofthe present invention, wherein FIG. 20(A) is a cross sectional viewillustrating a state in which the edge portions of two adjacent groupsof core segments are facing each other, and FIG. 20(B) is a crosssectional view illustrating a state in which the edge portions of thetwo adjacent groups of core segments have been engaged with each other.FIGS. 21(A) and 21(B) show a modified structure of the iron coreassembly of FIGS. 20(A) and 20(B) constructed according to the fourthembodiment of the present invention, wherein FIG. 21 (A) is a crosssectional view illustrating a state in which the edge portions of twoadjacent groups of core segments are facing each other, and FIG. 21(B)is a cross sectional view illustrating a state in which the edgeportions of the two adjacent groups of core segments have been engagedwith each other. FIGS. 20(A), 20(B) and FIGS. 21(A), 21(B) respectivelyshow different structures effective to expedite abutment of the oppositeend portions of laminated core members in forming laminated coresegments into a ring-shaped configuration through relative rotationthereof.

[0132] In the above figures, a reference numeral 18 represents an ironcore comprising a plurality of successively laminated core segments 18 ahaving their mutually confronting end edge portions successivelylaminated or overlapped one over another in a stepwise manner in thelaminating direction, as shown in FIGS. 20(A) and 20(B). Further, areference numeral 19 represents an iron core comprising a plurality ofsuccessively laminated core segments 19 a having their mutuallyconfronting end edge portions successively laminated or overlapped oneover another in a V-shaped manner in the laminating direction, as shownin FIGS. 21(A) and 21(B)

[0133] In this way, according to the fourth embodiment of the presentinvention, since the edge portions of the confronting ends of twoadjacent groups of core segments 18 a of a laminated core aresuccessively overlapped one over another in the laminating direction soas to form a stepwise or stairway configuration, as shown in FIGS. 20(A)and 20(B), there would be no limitation for the two groups of mutuallyconfronting core segments 18 a to move in the laminating direction.Therefore, during the above-mentioned bending operation, even if anundesired catch occurs in any of the above edge portions, such a catchis allowed to easily escape in the laminating direction. As a result, itis sure to easily eliminate a possible catch and smoothly perform apredetermined bending operation, so as to form a properly laminatedstructure for an iron core assembly and at the same time to improve adesired operational efficiency when assembling an iron core assembly ofthis kind. In addition, the core segments 18 at the confronting ends ofthe laminated core are engaged with one another in a surface-to-surfacecontact manner so magnetic resistance at the confronting ends of thelaminated core can be reduced.

[0134] Further, since the edge portions of the confronting ends of twoadjacent groups of core segments 19 a of a laminated core aresuccessively overlapped one over another so as to form a V-shapedconfiguration in the laminating direction, as shown in FIGS. 21(A) and21(B), there will be a desired limitation for the positions of some coresegments 19 a on the center of the whole lamination which corresponds toa crest of the V-shaped configuration. In this manner, during theabove-mentioned bending operation, even if an undesired catch occurs inany of the above edge portions, such a catch may be eliminated by addinga vibration in the laminating direction, thus making it possible toperform the bending operation in an easy and smooth manner and at thesame time improve a desired operational efficiency when assembling aniron core assembly of this kind. Also, the core segments 19 at theconfronting ends of the laminated core are engaged with one another in asurface-to-surface contact manner, reducing magnetic resistance at theconfronting ends of the laminated core.

[0135] Embodiment 5

[0136] FIGS. 22(A) through 22(D) are plan views schematicallyillustrating a method for assembling essential portions of an iron coreassembly constructed according to a fifth embodiment of the presentinvention. FIGS. 23(A) through 23(D) are cross sectional views takenalong an alternate long and short dash line in FIGS. 22(A) through22(D), respectively, as seen in the direction of arrows.

[0137] In these figures, reference numerals 20 and 21 represent a firstcore member and a second core member which are successively laminatedtogether. At corresponding positions of core segments 22, 23 which arethe opposite ends of the first and second core members 20, 21, there areformed holes 22 a and projections 23 a. The projections 23 b areengageable in the holes 22 a but are also freely disengageabletherefrom. In FIG. 22, the second core member 21 is represented byhatched portions.

[0138] In the following, an explanation will be given to describe themethod for assembling an iron core assembly having end portions asconstructed above.

[0139] At first, starting from the conditions shown in FIG. 22(A) andFIG. 23(A), the edge portions of respective core segments 22, 23 of thefirst and second core members 20, 21 at their opposite ends are causedto rotate with connection points (not shown) of their coupling means(e.g., concave and convex portions 3 a, 3 b in FIG. 3) serving asrotating centers. At this time, as shown in FIG. 22(B) and FIG. 23(B),the edge portions of core segments of odd number 23 at one end (i.e.,the left-hand side in these figures), and the edge portions of coresegments 22 of even number at the other end (i.e., the right-hand sidein these figures), are all caused to shift a little in a direction shownby an arrow in FIG. 22(B).

[0140] As a result, a hole 22 a in each core segment 22 and a projection23 a in each core segment 23 which have been engaged together areseparated from each other, so that each projection 23 a is moved towarda position not involving a hole 22 a so as to abut against a sidesurface of an adjacent core segment 23, thus increasing a clearancebetween mutually adjacent core segments 22, 23 corresponding to adistance by which the projection 23 a has been moved to come out of thehole 22 a. Next, as shown in FIG. 22(C) and FIG. 23(C), the coresegments 22, 23 at the opposite ends are drawn or moved toward eachother, so that the edge portions thereof are alternately overlapped oneover another with their projected edges at one end being inserted intocorresponding recesses defined between adjacent projected edges at theother end, thereby forming a ring-shaped iron configuration, as depictedin FIGS. 22(D) and 23(D). Then, the adjacent core segments 22, 23 of thefirst and second core members 20, 21 are again moved relative to oneanother in a direction just opposite or reverse to the directionindicated at an arrow in FIG. 22(B), so that the projections 23 a on thecore segments 23 are inserted or engaged into the corresponding holes 22a in the core segments 22, thus completing an assembling operation.

[0141] As described above, according to the fifth embodiment of thepresent invention, on corresponding positions of respective coresegments 22, 23 of the laminated first and second core members 20, 21there are formed holes 22 a and projections 23 a. The projections 23 bcan be placed into or out of engagement with the holes 22 a. Inassembling operation, the projections 23 a are detached or disengagedfrom the holes 22 a so as to enlarge widthwise clearances betweenadjacent core segments 22, 23. As a result, the abutting engagementsbetween the first and second core members 20, 21 can be made easily,thereby improving an operational efficiency when assembling an iron coreassembly of this type.

[0142] Embodiment 6

[0143]FIG. 24 is a front view illustrating the structure of an iron coreassembly constructed according to a sixth embodiment of the presentinvention. FIG. 25 is a plan view showing how core members of FIG. 24are formed through press-punching.

[0144] In these figures, a reference numeral 24 generally represents apair of first core members each having at the center thereof aprotruding magnetic pole tooth 24 a wound by a coil (not shown), and areference numeral 25 generally represents a pair of second core memberseach having core segments rotatably or articulately connected with eachother at their adjacent ends thereof. Each first core member 24comprises a plurality of first core segments laminated one over another,and each second core member 25 comprises a plurality of core layerslaminated one over another, each core-layer including two second coresegments disposed in a line and rotatably connected with each otherthrough a coupling means or mechanism, as shown in FIG. 24. For example,each second core member 25 is equivalent to a core member 4 or 5 of theabove-mentioned first embodiment which has two core segments 3 perlayer. Thus, each second core member 25 can be constructed substantiallyin the same manner as the core members 4, 5. By rotating second coresegments of the second core members 25 relative to each other throughthe coupling means, the pair of first core members 24 and the pair ofsecond core members 25 are combined into abutting engagement with eachother at their ends, thereby providing a ring-shaped (e.g.,rectangular-shaped) iron core assembly 26.

[0145] In this way, according to the sixth embodiment of the presentinvention, since the ring-shaped iron core assembly 26 is constructed byproperly connecting the first core members 24 and the second coremembers 25, when the first core members 24 and the second core members25 are formed from a sheet of plate-shaped material by means of apress-punching processing, it is allowed to arrange the first and secondcore members 24 and 25 in the narrowest possible space, as shown in FIG.25, thereby improving the yield of the core materials.

[0146] Embodiment 7

[0147]FIG. 26 is a plan view of an iron core assembly in accordance witha seventh embodiment of the present invention, but showing a statebefore assemblage thereof, and FIG. 27 is a plan view of the iron coreassembly of FIG. 26, showing its completed state.

[0148] In FIG. 26, the iron core assembly of this embodiment comprises afirst laminated core unit 93, a second laminated core unit 94 and athird laminated core unit 95. Here, note that these three core units 93,94 and 95 are equivalent to three circumferentially divided componentsof the laminated iron core assembly of the above-mentioned firstembodiment shown in FIG. 1. Thus, each of the three laminated core units93, 94 and 95 are formed in the same as the laminated core members 4, 5of the first embodiment. That is, each of the laminated core units 93,94 and 95 includes a first core member comprising a plurality of flat orplate-shaped core segments successively disposed in a raw, and a secondcore member comprising a plurality of flat or plate-shaped core segmentssuccessively disposed in a raw. The first and second core members arelaminated one over another with inter-segment positions of clearancesbetween adjacent core segments of each first core member being displacedfrom those of an adjacent second core member in the longitudinaldirection, so that edge portions of core segments adjoining each otherin the laminating direction are overlapped with each other. Mutuallyadjacent edges of core segments adjoining each other are connected witheach other through coupling means in the form of concave and convexportions 3 a, 3 b. At the opposite ends 96, 97 of each laminated coremembers, there is no provision of coupling means in order to allow theopposing ends 96, 97 to be combined into abutting engagement with eachother.

[0149] Although in the first embodiment of FIG. 1, the respective coresegments are rotated or articulated relative to each other to form thelaminated core members as a single core unit into a ring-shapedconfiguration to provide a completed iron core assembly, according tothe seventh embodiment shown in FIGS. 26, 27, the respective coresegments of the laminated iron core assembly, after each being wound bya wire (not shown), are rotated through the coupling means to combinethe first, second and third laminated core units 93, 94 and 95 togetherinto a ring-shaped configuration, thus providing an iron core assembly 9for use with an electric motor (see FIG. 27). In FIG. 27, referencenumerals 99, 100 and 101 represent connector portions for couplingadjacent ends of the respective laminated core units 93, 94 and 95 witheach other. In this manner, in the case of the circumferentially dividedconstruction of the laminated core assembly, the core assembly can bedivided into a plurality of core units each having a size suitable forexpediting a variety of operations as desired, thus improving theoperating efficiency.

[0150] Embodiment 8

[0151]FIG. 28 is a plain view schematically showing the structure of aniron core assembly constructed according to an eight embodiment of thepresent invention. FIG. 29 is a plan view schematically showing thestructure of core segments of FIG. 28. FIG. 30 is a plan viewschematically showing essential portions of modified forms of coresegments different from those shown in FIG. 29. FIG. 31 is a viewsimilar to FIG. 30, but showing a different operating state in which thecore segments of FIG. 30 have been formed into a ring-shapedconfiguration. FIG. 32 is a view similar to FIG. 30, but showing anothermodified forms of core segments. FIG. 33 is a view similar to FIG. 32,but showing a different operating state in which the core segments shownin FIG. 32 have been formed into a ring-shaped configuration.

[0152] In the above-identified figures, the same parts as those shown inthe first embodiment are represented by the same reference numerals andhence a description thereof is omitted. In these figures, referencenumerals 27 and 28 represent rotation restricting means in the form ofengaging portions or projections which are formed on the end faces 3 c,3 d of each core segment 3 to protrude in a direction to restrict therelative rotation of the core segments 3. The engaging projections 27,28 on one and the other end faces 3 c, 3 d, respectively, of mutuallyadjacent core segments 3 of the first and second core members 4, 5 onthe same planes or layers are placed in abutting engagement with eachother to prevent relative rotation between the mutually adjacent coresegments 3 when a plurality of core first and second members 4, 5alternately laminated one over another are connected at their oppositeends to be formed into a ring-shaped configuration. With the engagingprojections 27, 28 at their mutually contacted positions, the first andsecond core members 4, 5 are respectively connected at their ends toform a ring-shaped configuration, thereby providing a desired iron coreassembly 7, as shown in FIG. 28.

[0153] In this way, according to the eighth embodiment of the presentinvention, on the respective end faces 3 c, 3 d of each core segment 3,there are formed engaging portions 27, 28 which can be placed intoabutting engagement with each other to prevent relative rotation betweenthe adjacent core segments 3 when the core members 4, 5 are respectivelyconnected at their ends with each other to form a ring-shapedconfiguration. With this arrangement, it becomes easy to properlyposition the respective core segments 3 of the first and second coremembers 4, 5 in forming these core members 4, 5 into a ring-shapedconfiguration, thereby improving an operational efficiency whenassembling an iron core assembly.

[0154] Further, as shown in FIG. 30 and FIG. 32, one 29 or 31 ofengaging portions at one end of a core segment 3 may be formed into adeformable shape, and the respective core segments 3 can be properlypositioned by use of jigs so as to form a ring-shaped configuration, sothat the one engaging portion 29 or 31 is deformably forced into fittingengagement with the other engaging portion 30 or 32. With thisconstruction, it is possible to bear a radial force acting on the firstand second core members 4, 5, which are formed into a ring-shapedconfiguration, through the engaging portions of mutually adjacent coresegments 3, thereby providing an iron core assembly suitable for use inan electric motor which requires an adequate mechanical strength in theradial direction thereof.

[0155] Moreover as shown in FIG. 30 and FIG. 32, on the respective endfaces 3 c, 3 d of each core segment 3 at positions different from theengaging portions 29, 30, 31 and 32, there may be formed areverse-rotation restricting means in the form of additional engagingportions 33, 34 which can be placed into abutting engagement with eachother upon a reverse rotation of adjacent core segments 3 in a directionopposite the rotating direction thereof in forming the ring-shapedconfiguration, thus for preventing the reverse rotation. With thisconstruction, by restricting the reverse rotation at each connectionpoint between adjacent core segments 3, it is sure to prevent a possiblerebound of a core member during a process for winding a coil, therebyimproving an assembling operation of an iron core assembly.

[0156] In addition, as shown in FIG. 34 and FIG. 35, on the engagingportions 33, 34, 35 and 36 of each core segments 3, there may be formedengaging projections 33 a, 34 a, 35 a and 36 a, respectively, so thatwhen the engaging portions 33, 34 are in abutment with the engagingportions 35, 36, respectively, the engaging projections 33 a, 34 a willalso come into abutment with the engaging portions 35 a, 36 a,respectively, thus temporarily fixing the core segments in suchpositions. As a result, it is sure to easily perform a wire windingoperation for forming coils on the iron core assembly, and easilyperform an operation for properly bending the core members, therebyimproving an operational efficiency in assembling the iron coreassembly.

[0157] Embodiment 9

[0158]FIG. 36 is a developed perspective view showing the structure ofan iron core assembly constructed according to a ninth embodiment of thepresent invention.

[0159] In FIG. 36, the same portions as those shown in the firstembodiment are represented by the same reference numerals, and hence adescription thereof is omitted. In this figure, reference numerals 37,38, 39 represent a first, a second and a third cylindrical-shapedinsulating bobbin each having a pair of flange portions 37 a, 38 a, 39a, respectively. The first insulating bobbin 37 is comprised of a pairof half-pieces 37 b, 37 b divided in the vertical direction. The secondinsulating bobbin 38 is comprised of a pair of half-pieces 38 b, 38 bdivided in the longitudinal direction. The third insulating bobbin 39 isformed integral with core segments 3. Further, these insulating bobbins37, 38, 39 serve to integrally hold a plurality of core segments 3 bymeans of their cylindrical bodies, the core segments 3 being disposedone over another in a laminating direction of the laminated first andsecond core members 4, 5,

[0160] In this manner, according to the ninth embodiment of the presentinvention, the plurality of core segments 3 disposed one over another inthe laminating direction of the laminated first and second core members4, 5 can be integrally held together by the insulating bobbins 37, 38,39, ensuring a desired integration without bringing about anyunfavorable influence such as a strain or distortion of the coresegments 3. As a result, a possible increase in magnetic resistance canbe effectively suppressed and thus a magnetic performance can beimproved. Although in the above description three kinds of insulatingbobbins 37, 38, 39 are employed, it goes without saying that one or two-kinds of insulating bobbins, for example the insulating bobbin 37 alone,can be used to obtain substantially the same effects.

[0161] Though not mentioned in the above first through eighthembodiments, after the respective core segments are rotated relative toone another through the respective coupling portions so as to bend therespective core members into a ring-shaped configuration, the respectivecoupling portions may be fixedly secured through welding or the like, sothat the rigidity of the respective core members can be significantlyincreased, making it possible to provide an iron core assembly withexcellent mechanical strength.

[0162] Further, although it has been described in the above firstthrough ninth embodiments that the present invention is applied to aniron core assembly for an electric motor, it is to be understood thatthe present invention is not limited to such specific examples. Forinstance, as illustrated in FIG. 37, a laminated core may comprise aplurality of in-line core segments 40 (without any magnetic pole tooth)in place of the core segments each having a magnetic pole tooth asemployed in the first embodiment. The laminated core, after having beenwound with wires 41, are bent about coupling portions through theirrelative rotation to form a ring-shaped or rectangular-shaped iron coreassembly, as shown in FIG. 38. The iron core assembly thus formed canoff course be used for a transformer such as zero-phase-sequence currenttransformer and the like with substantially the same effects asdescribed above. In the case of the iron core assembly used for acurrent transformer, it is preferred that the abutting engagement of theopposite ends of the laminated core be achieved by surface-to-surfaceabutments in the edge portions of core segments adjoining each other inthe laminating direction thereof, so as to reduce magnetic resistance atthe opposite ends of the laminated core.

[0163] Embodiment 10

[0164]FIG. 39 is a plan view of an iron core assembly according to atenth embodiment of the present invention, but showing its state beforeassembling, and FIG. 40 is a plan view of the iron core assembly of FIG.39 after assemblage thereof.

[0165] In FIG. 39, the iron core assembly of this embodiment includes afirst laminated core unit 111 and a second laminated core unit 112. Infact, the iron core assembly of this embodiment is equivalent to thelaminated core of the ninth embodiment shown in FIG. 37 that is dividedinto two laminated core units, and the first and second laminated coreunits 111, 112 are constructed just in the same manner as the laminatedcore of FIG. 37.

[0166] Specifically, the first laminated core unit 111 is comprised of aplurality of first core members each having three plate-shaped firstcore segments (having no magnetic pole tooth) successively disposed in aline, and a plurality of second core members each having threeplate-shaped second core segments (having no magnetic pole tooth)successively disposed in a line. The first and second core members arealternately laminated one over another in such a manner that respectivefirst inter-segment positions (i.e., clearances or interstices betweenadjacent core segments of each first core member) are displaced oroffset from respective second inter-segment positions (i.e., clearancesor interstices between adjacent core segments of each second coremember) in the longitudinal direction of the first and second coremembers, with end edge portions of the respective core segmentsadjoining each other in the laminating direction being overlapped eachother. The adjacent end edges of the adjoining core segments areconnected with each other by virtue of coupling means in the form ofconcave and convex portions 3 a, 3 b mutually engageable with eachother. The first laminated core unit 111 has opposite ends 113, 114 eachformed into a concave-convex configuration in which concaves andconvexes defined by alternately laminated first and second core segmentsof the first and second core members are alternately disposed in thelaminating direction.

[0167] The second laminated core unit 112 is comprised of a plurality offirst core members each having one plate-shaped first core segment(having no magnetic pole tooth), and a plurality of second core memberseach having one plate-shaped second core segment (having no magneticpole tooth). The first and second core members are alternately laminatedone over another in such a manner that the first and second core membersare displaced or offset from each other in the longitudinal direction ofthe first and second core members. Similar to the first laminated coreunit 111, the second laminated core unit 112 has opposite ends 113, 114each formed into a concave-convex configuration in which concaves andconvexes defined by alternately laminated first and second core segmentsof the first and second core members are alternately disposed in thelaminating direction.

[0168] Here, note that in order for adjacent ends 113, 114 of the firstand second laminated core units 111, 112 to be alternately inserted intoeach other and placed into mutual abutting engagement in a smoothmanner, there is provided no coupling means (i.e., concave and convexportions 3 a, 3 b) at the opposite ends 113, 114 of the first coreunits.

[0169] Although in the ninth embodiment of FIG. 37, a single laminatedcore unit as a whole is formed into a rectangular configuration byrotating the respective core segments 40 relative to each other toprovide an iron core assembly, in the tenth embodiment shown in FIGS.39, 40, the respective core segments of the first laminated core unit111, after having been wound with wires (not shown), are rotatedrelative to each other through the coupling means (i.e., the engagedconcave and convex portions 3 a, 3 b) so that the concaves and convexesat the opposite ends 113, 114 of the first and second laminated coreunits 111, 112 are mutually inserted and combined with each other toform a rectangular configuration, thus producing an iron core assembly40 for use with a transformer, as shown in FIG. 40. In this manner,assembling divided laminated core units serves to improve an operationalefficiency because the entire laminated core can be divided into aplurality of core units having a size suitable for handling or working.

[0170] Embodiment 11.

[0171]FIG. 41 is a front view showing the structure of an iron coreassembly for a zero-phase-sequence current transformer according to aeleventh embodiment of the present invention. FIGS. 42(A) and 42(B) areplan views illustrative of process steps for a method of assembling coremembers of the iron core assembly of FIG. 1. FIG. 43 is an operationdiagram illustrative of process steps for bending the core members byrotating or turning coupling means. FIGS. 44(A) through 44(B) are viewsfor explaining the principle of the present invention.

[0172] In these figures, an iron core assembly 57 includes a pluralityof first and second core members 53, 56 which are alternately laminatedone over another.

[0173] As shown in FIG. 42(A), each first core member 53 comprises aplurality of two kinds of first core segments 51, 52 which aresuccessively and alternately disposed in a line with a clearance formedtherebetween. One kind of first core segments 51 are each made of a flator plate-shaped magnetic material and provided on its front and backsurfaces at its one end with a concave portion 51 a and a convex portion51 b serving as a coupling means. The other kind of first core segments52 are each made of a flat or plate-shaped magnetic material as in thecase of the one kind of first core segments 51, and provided in its bodywith a notched portion 52 a around which a wire (not shown) is wound,and on its front and back surfaces at its one end with a concave portion52 b and a convex portion 52 c serving as a coupling means.

[0174] Similarly, each second core member 56 comprises a plurality oftwo kinds of second core segments 54, 55 which are successively andalternately disposed in a line with a clearance formed therebetween. Onekind of second core segments 54 are each made of a flat or plate-shapedmagnetic material and provided on its front and back surfaces at theother end thereof with a concave portion 54 a and a convex portion 54 bserving as a coupling means. The other kind of second core segments 55are each made of a flat or plate-shaped magnetic material as in the caseof the one kind of second core segments 54, and provided in its bodywith a notched portion 55 a around which a wire (not shown) is wound,and on its front and back surfaces at the other end thereof with aconcave portion 55 b and a convex portion 55 c serving as a couplingmeans.

[0175] The concave and convex portions 51 a, 51 b and 52 b, 52 c of thefirst core segments 51 and 52, respectively, and the concave and convexportions 54 a, 54 b and 55 b, 55 c of the second core segments 54 and55, respectively, are provided at a location 62 which is on the outerside (i.e., on the side opposite the center of the iron core assemblyfor the zero-phase-sequence current transformer) away from anintersection 60 of widthwise centerlines 54 x (51 x) and 55 x (52 x) ofthe respective core segments 54 (51) and 55 (52), and which is on abisector 61 for an angle formed by the two centerlines 54 x (51 x) and55 x (52 x), as shown in FIG. 44(A). In this connection, note that thewidthwise centerlines of the core segments 52, 55 having the notchedportions 52 a, 55 a, respectively, are the same as those of the coresegments 52, 55 having no notched portions.

[0176] As shown in FIG. 42(B), a plurality of first core members 53 anda plurality of second core member 56 are alternately stacked orlaminated in a manner such that first inter-segment positions (i.e.,clearances or interstices between every two adjacent core segments 51,52) of each first core member 53 are displaced or offset from secondinter-segment positions (i.e., clearances or interstices between everytwo adjacent core segments 54, 55) of each second core member 56, withthe edge portions of core segments adjoining each other in thelaminating direction of the first and second core members 53, 56 beingoverlapped each other. In the end edge portions of core segments 51, 52,54, 55 that are adjacent in the laminating direction, the concave andconvex portions 51 a, 52 b and 51 b, 52 c of the core segments 51 and 52of the first core member 53 are respectively engaged with thecorresponding concave and convex portions 55 b, 55 c and 54 a, 54 b ofthe core segments 55 and 54 of the second core member 56 to rotatablycouple the core segments.

[0177] Then, the first and second core members 53, 56 are formed insuccession by press-punching, and in a step for stacking or laminatingthem, the respective concave and convex portions 51 a, 52 b and 51 b, 52c, which are opposed to each other in the direction in which the coresegments 51, 52, 54, 55 are stacked or laminated, are engaged with eachother, and formed into one piece by caulking at, for example, thepositions indicated by arrows in FIG. 42(B) thereby to make a laminatedcore unit 57. After wires (not shown) are wound around the notchedportions 52 a, 55 a of the core segments 52, 55, the laminated first andsecond core members 53, 56 are bent by rotating or turning the laminatedcore segments 51, 52, 54, 55 around the engaged concave and convexportions 51 a, 52 b and 51 b, 52 c to form them into a rectangularshape, thus completing an iron core assembly 58, as shown in FIG. 41.

[0178] According to the iron core assembly 58 of the eleventh embodimentas constructed above, the position of each of coupling means or sectionsof the first core segments 51, 52 of the first core member 53 and thesecond core segments 54, 55 of the second core member 56, i.e., theposition of each of concave and convex portions, is set at the location62 which is on the outer side (i.e., on the side opposite the center ofthe iron core assembly for the zero-phase-sequence current transformer)away from the intersection 60 of the widthwise centerlines 54 x (51 x)and 55 x (52 x) of the core segments 54 (51) and 55 (52), and which ison the bisector 61 for the angle formed by the two centerlines 54 x (51x) and 55 x (52 x), as shown in FIG. 44(A). Hence, the opposing endfaces 51 c, 52 e and 54 c, 55 e of adjacent two core segments 51, 52 and54, 55 are abutted against each other in full contact when the iron coreassembly 58 has been fabricated, whereas an appropriate clearance or gap59 can be allowed therebetween when press-cutting adjacent two coresegments 51, 52 and 54, 55, as shown in FIG. 42(A). Thus, easypress-punching operation can be accomplished without causingdeterioration in the magnetic performance of the iron core assembly 58.

[0179] If the position of each of concave and convex portions 54 a (51a), 54 b (51 b) and 55 b (52 b), 55 c (52 c) were set at the samelocation where the intersection 60 of the centerlines 54 x (51 x) and 55x (52 x) exists as shown in FIG. 4(B), then the opposing end faces 51 c,52 e and 54 c, 55 e of adjacent two core segments 51, 52 and 54, 55would be in contact at the time of press-punching. Therefore, thepress-punching operation would be difficult although the magneticperformance would not be deteriorated.

[0180] On the other hand, if the position of each of concave and convexportions 54 a (51 a), 54 b (51 b) and 55 b (52 b), 55 c (52 c) were setat ajocation 63 on the centerline 55 x (52 x) and on the outer side awayfrom the intersection 60 of the centerlines 54 x (51 x) and 55 x (52 x)as shown in FIG. 44(C), then a clearance or gap would be formed betweenthe opposing end faces 51 c, 52 e and 54 c, 55 e of adjacent two coresegments 51, 52 and 54, 55 when press-punching them, making thepress-punching operation easy, whereas the yield of the core materialswould be reduced because of a difference y₁ in level produced betweenadjacent two core segments. In this regard, however, though it ispreferred that the position of each concave and convex portion is set atthe location 62 which is on the outer side away from the intersection 60and on the bisector 61, if the difference y₁ is allowed, it is feasibleto set the position of each concave and convex portions at a location onthe centerline 55 x (52 x) and on the outer side a certain distance(within the allowable difference y₁) away from the bisector 61.

[0181] Further, if the position of each of concave and convex portions54 a (51 a), 54 b (51 b) and 55 b (52 b), 55 c (52 c) were set at alocation 64 on the centerline 55 x (51 x) and on the inner side from thecenterline 54 x (51 x) as shown in FIG. 44(D), then a difference y₁ inlevel would be produced between adjacent two core segments 54 (51) and55 (52) when press-punching them, with a resultant lower yield of thecore materials as in the case shown in FIG. 4(C) and there would be alsoa problem in that the press-punching could not be effected because theend faces 51 c, 52 e and 54 c, 55 e of adjacent two core segments 51, 52and 54, 55 would overlap each other by an amount of difference y₂.

[0182] Embodiment 12

[0183]FIG. 45 is a front view showing the structure of an iron coreassembly for an electric motor according to a twelfth embodiment of thepresent invention. FIGS. 46(A), 46(B) and 46(C) are plan viewsrespectively showing process steps of a method of assembling coremembers of the iron core assembly of FIG. 45. FIGS. 47(A) and 47(B) areplan views respectively showing the structure of essential portions ofthe iron core assembly of FIG. 46 but in their different states.

[0184] In FIG. 45, an iron core assembly 77 includes a plurality offirst and second core members 72, 74 which are alternately laminated oneover another, as shown in FIG. 46(A).

[0185] As shown in FIG. 46(B), each first core member 72 comprises aplurality of first core segments 71 which are successively disposed sideby side in a line with a clearance or gap formed therebetween. The firstcore segments 71 are each made of a flat or plate-shaped magneticmaterial and provided on its front and back surfaces at its one end witha concave portion 71 a and a convex portion 71 b serving as a couplingmeans. Each of first core segments 71 has a convex-shaped end face 71 cat one end thereof, a concave-shaped end face 71 d at the other endthereof which is complementary in shape to and engageable with aconvex-shaped end face 73 c of an adjacent first core segment 71, and amagnetic pole piece 71 e which extends inward from the center thereofand around which a wire (not shown) is wound.

[0186] Similarly, each second core member 74 comprises a plurality ofsecond core segments 73 which are successively disposed side by side ina line with a clearance formed therebetween. The second core segments 73are each made of a flat or plate-shaped magnetic material and providedon its front and back surfaces at the other end thereof with a concaveportion 73 a and a convex portion 73 b serving as a coupling means. Eachof second core segments 73 has a concave-shaped end face 73 d at one endthereof, a convex-shaped end face 73 c at the other end thereof which iscomplementary in shape to and engageable with a concave-shaped end face73 d of an adjacent second core segment 73, and a magnetic pole piece 73e which extends inward from the center thereof and around which a wire(not shown) is wound.

[0187] The concave and convex portions 71 a, 73 a and 71 b, 73 b of thefirst and second core segments 71 and 73, respectively, are eachprovided at a location 76 which is on the outer side (i.e., on the sideopposite the center of the iron core assembly for the electric motor)away from an intersection 74 of widthwise centerlines 73 x (71 x) and 73x (71 x) of the respective core segments 73 (71) and 73 (71), and whichis on a bisector 75 for an angle formed by the two centerlines 73 x (71x) and 73 x (71 x), as shown in FIG. 47(A). In this connection, notethat the widthwise centerlines 73 x, 71 x of the core segments 73, 71,respectively, are a little different at their ends and center, but thismakes substantially no difference from a practical point of view.

[0188] As shown in FIG. 46(A), a plurality of first core members 72 anda plurality of second core members 74 are alternately stacked orlaminated in a manner such that first inter-segment positions (i.e.,clearances or interstices between every two adjacent core segments 71,71) of each first core member 72 are displaced or offset from secondinter-segment positions (i.e., clearances or interstices between everytwo adjacent core segments 73, 73) of each second core member 74, withthe edge portions of core segments adjoining each other in thelaminating direction of the first and second core members 72, 74 beingoverlapped each other. In the end edge portions of core segments 71, 73that are adjacent in the laminating direction, the concave and convexportions 71 a, 71 b of the core segments 71 of the first core member 72are respectively engaged with the corresponding convex and concaveportions 73 b, 73 a of the core segments 73 of the second core member 74to rotatably couple the core segments.

[0189] Then, the first and second core members 72, 74 are formed insuccession by press-punching, and in a step for stacking or laminatingthem, the respective concave and convex portions, which are opposed toeach other in the direction in which the first and second core members72, 74 are stacked or laminated, are engaged with each other, and formedinto one piece by caulking at, for example, the central positions of thecore segments thereby to make a laminated core unit 77, as shown in FIG.46(A). After wires (not shown) are wound around the magnetic pole teeth71 e of the core segments 71, 73, the laminated first and second coremembers 72, 74 are bent by rotating or turning the laminated coresegments 71, 73 around the engaged concave and convex portions 71 a, 73b and 71 b, 73 a to form them into a rectangular shape, thus completingan iron core assembly 78, as shown in FIG. 45.

[0190] According to the twelfth embodiment as constructed above, theposition of each of coupling means or sections of the respective coresegments 71, 73, i.e., the position of each of concave and convexportions, is set at the location 76 which is on the outer side (i.e., onthe side opposite the center of the iron core assembly for the electricmotor) away from the intersection 74 of the widthwise centerlines 73 x,73 x of the core segments 73 (71) and 73 (71) adjoining each other inthe laminating direction, and which is on the bisector 75 for an angleformed by the two centerlines 73 x (71 x) and 73 x (71 x), as shown inFIG. 47(A). Thus, the opposing end faces 73 c, 73 d and 71 c, 71 d ofadjacent two core segments 73, 73 and 71, 71 are abutted against eachother in full contact when the iron core assembly 78 has been fabricatedas shown in FIG. 47(A), whereas an appropriate clearance or gap 79 canbe allowed therebetween when press-cutting adjacent two core segments73, 73 and 71, 71, as shown in FIG. 47(B). Thus, easy press-punchingoperation can be accomplished without causing deterioration in themagnetic performance of the iron core assembly 79.

[0191] If the position of each of concave and convex portions 71 a, 73 aand 71 b, 73 b were set at a location 80 which is on a centerline 73 x(71 x) (i.e., left-hand one in FIG. 47(A)) of a core segment 73 and tothe right from a bisector 75 for an angle formed by the centerlines 73 x(71 x) and 73 x (71 x) as shown in FIG. 47(A), then a clearance or gapwould be formed between the opposing end faces 73 c, 73 d and 71 c, 71 dof adjacent two core segments 73, 73 and 71, 71 when press-punchingthem, making the press-punching operation easy, whereas the yield of thecore materials would be reduced because of a difference y₁ in levelproduced between adjacent two core segments 73, 73 or 71, 71, as shownin FIG. 44(C). In this regard, however, though it is preferred that theposition of each concave and convex portion is set at the location 76which is on the outer side away from the intersection 74 and on thebisector 75, if the difference y₁ is allowed, it is feasible to set theposition of each concave and convex portions at a location on thecenterline 73 x (71 x) and on the outer side a certain distance (withinthe allowable difference y₁) away from the bisector 75.

[0192] FIGS. 48(A) and 48(B) are plan views respectively showingessential portions of adjacent core segments disposed in acircumferential direction of the core assembly but with differentcoupling means between the adjacent core segments. In FIGS. 48(A) and48(B), the same symbols as those in FIG. 47 designate the correspondingparts in FIG. 47. In FIG. 48(A), a core segment 73 is formed at one endthereof with one end face which comprises a concave arc-shaped portionand a straight line portion, and at the other end with the other endface which comprises a convex arc-shaped portion complementary in shapeto the concave arc-shaped portion and a straight line portion. When theadjacent core segments 73 are turned or rotated relative to each otheraround a location 76 of a coupling means or section to form an annularor ring-shaped iron core assembly, the adjacent end faces thereof comeinto abutting engagement along their entire length with each other. FIG.48(A) shows the state of such abutting engagement. In FIG. 48(B), eachcore segment 73 has one end face comprising a straight line, and theother end face formed into a convex-shaped or angular configurationcomprising two straight lines. When the adjacent core segments arerelatively turned or rotated about a location 76 of a coupling means toform an annular or ring-shaped core assembly, the adjacent end facesthereof are partially placed into abutting engagement with each other.FIG. 48(B) shows the state of such partial abutting engagement.

[0193] Here, note that in the eleventh and twelfth embodiments, thecoupling means may comprise a pin and hole connection, as shown in FIG.3, in place of the concave and convex connection.

[0194] Moreover, although in the above-mentioned eleventh and twelfthembodiments reference has been made to an iron core assembly for azero-phase-sequence current transformer and one for an electric motor,respectively, it goes without saying that the present invention is notlimited to these but may be applied to other electric equipment such asgeneral transformers with substantially the same effects.

[0195] Embodiment 13

[0196]FIGS. 49 through 57 are perspective views sequentially showingprocess steps for fabricating an iron core assembly suitable for amedium-sized electric motor in accordance with a thirteenth embodimentof the present invention. FIGS. 49(A) and 49(B) are perspective views ofa core segment block, showing a core pressing process. FIG. 50 is aperspective view of core segment blocks stacked or laminated in a row,showing an axially coupling process therefor. FIG. 51 is a developedperspective view of three-teeth core segment blocks, showing a stackingand arraying process. FIG. 52 is a developed perspective view ofthree-teeth core segment blocks, showing a three-teeth temporal orpreliminary coupling process. FIG. 53 is a developed perspective view ofthree-teeth core segment blocks showing an insulation piece assemblingprocess. FIG. 54 is a perspective view of three-teeth core segmentblocks showing a wire-winding process. FIG. 55 is a perspective viewshowing a three-teeth blocking and fixing process. FIG. 56 is adevelopment view of an iron core assembly, showing a circularly couplingprocess. FIG. 57 is a perspective view of the iron core assembly,showing a wiring, varnishing, and shrinkage fitting process.

[0197] In the iron core assembly according to the thirteenth embodiment,a plurality of core segments 14 as in FIG. 17 of the third embodimentare stacked or laminated to form a core segment block, and hence a firstcore member is not formed of a single layer but of a plurality of layers(for instance, 100 layers). Also, a second core member is not formed ofa single layer but of a plurality of layers. The fabrication processaccording to this embodiment will be described below in sequence.

[0198] In FIG. 49(A), a reference numeral 81 designates a planar or flatgenerally T-shaped core segment formed of a magnetic material. Each coresegment 81 has a magnetic pole tooth 81 b with a hole 81 c formedtherethrough and a head or cross piece 81 d integrally formed therewith.The cross piece 81 d has a hole 81 a formed therethrough at one end edgeportion thereof. The cross piece 81 d is formed at one end thereof witha convex arc-shaped end face and at the other end with a concavearc-shaped end face which is complementary in shape to and engageablewith a convex arc-shaped end face of an adjacent core segment. The coresegment 81 is about 0.5 mm thick for example, and formed bypress-punching, and about 100 pieces of core segments 81 are stacked toform a first core segment block 82. Though not shown, the respectivecore segments of the first core segment block 82 are, for example,placed into concave-convex engagement with each other so as to beintegrally united together through caulking.

[0199] To this end, the first core segment block 82 as a whole has ahole 82 a formed therethrough in the one end edge portion thereof, thehole 82 a constituting a part of the coupling means. In this case, thehole 82 a comprises a plurality of holes 81 a in the respective coresegments 81 of the first core segment block 82. The first core segmentblock 82 as a whole has a convex arc-shaped end face formed at one endthereof and a concave arc-shaped end face formed at the other endthereof so as to be engageable with an end face of an adjacent coresegment block. Moreover, the first core segment block 82 has a magneticpole tooth 82 b which comprises a plurality of magnetic pole teeth 81 bof the respective core segments 81 thereof, and a hole 82 c whichcomprises a plurality of holes 81 c in the respective core segments 81thereof. A plurality of first core segment blocks 82 are disposed orarrayed in succession to form a first core segment member.

[0200] A second core segment block 83 shown in FIG. 49(B) is the reverseof the first core segment block 82, i.e., the one end edge portionthereof and the other end edge portion thereof being reversed withrespect to each other. The second core segment block 83 has a hole 83 aformed therethrough in the other end edge portion thereof, serving as apart of the coupling means, and a convex arc-shaped end face formed atone end thereof. The second core segment block 83 is formed at one endthereof with a concave arc-shaped end face engageable with an end faceof an adjacent core segment block, a magnetic pole tooth 83 b and a hole83 c. A plurality of second core segment blocks 83 are disposed orarrayed in succession to form a second core member.

[0201]FIG. 50 shows a plurality of first core segment blocks 82 and aplurality of second core segment blocks 83 alternately stacked orlaminated one over another to form a one-tooth layer. In this case,three first core segment blocks 82 and two second core segment blocks 83are stacked. In this regard, however, note that three first core segmentblocks 82 may be successively stacked, and two second core segmentblocks 83 may then be stacked successively thereon. A reference numeral84 generally designates one tooth of stacked or laminated core segmentblocks. A pin member 85 is passed through the holes 82 c and 83 c in thefirst and second core segment blocks 82 and 83 to hold the one-toothstacked core segment blocks 84 in their entirety in such a manner thatthey are rotatable relative to each other but coupled or jointed witheach other in an axial direction. The pin member 85 may comprise a boltand a nut.

[0202] When three-teeth first core segment blocks 82 and three-teethsecond core segment blocks 83 are stacked in an array, they are stacked,for example, as shown in FIG. 51, but they can otherwise be stacked inany different and efficient manner independently of the direction ofstacking and the direction of arraying. Thereafter, the thus stackedblocks are axially connected with each other tooth by tooth by means ofthe pin members 85 so as to be rotatable there around relative to eachother. Here, note that reference numerals 82 and 83 in FIG. 51 designatea first core segment block and a second core segment block,respectively.

[0203] In an initial state shown in FIG. 52, the hole 82 a (part of thecoupling means) in the one end edge portion of each first core segmentblock 82 and the hole 83 a (part of the coupling means) in the other endedge portion of each second core segment block 83 are aligned incommunication-with each other in the stacking or laminating direction.Thus, the pin member 86 (part of the coupling means) is passed throughthese holes 82 a, 83 a to connect or joint the respective first andsecond core segment blocks 82, 83 with respect to each other tooth bytooth for rotation relative to each other. In this manner, three-teethtemporal or preliminary connections of three-teeth blocks 87 havingstacked three teeth 84 are effected.

[0204] Next, an insulation piece assembling process will be describedwhile referring to FIG. 53. In the three-teeth blocks 87 comprising thefirst and second core segment blocks 82 and 83 thus stacked and arrayed,the opposite sides of each tooth 84 are covered with insulation pieces88, and the opposite ends of each tooth 84 are covered with insulationcaps 89. In this manner, the teeth portions are covered with aninsulating material in order to protect windings. In FIGS. 54 and 55which illustrate the following assembling process steps, neitherinsulation pieces 88 nor insulation caps 89 are shown.

[0205]FIG. 54 illustrates a wire winding process in which three teeth 84of the three-teeth blocks 87, being connected with each other by thecoupling means comprising holes 82 a, 83 a and pins 86 insertedtherethrough, are respectively turned or rotated tooth by tooth aboutthe related pin members 86 with respect to each other so as to open orwarp in a reversely or outwardly turned manner with an interval or spanbetween the tip ends of adjacent teeth 84 being expanded from eachother. In this reversely or outwardly warped state, each tooth 84 iswound by a winding wire by means of a wire supply nozzle 90 of a wirewinding machine. Note that the winding wires are omitted and not shownin the figures showing the following process steps.

[0206]FIG. 55 shows a three-teeth blocking and fixing process in whichthe teeth 84 of the three-teeth blocks 87 are respectively turned aboutthe coupling means so as to take a positively or inwardly warped orcurved state, thus reducing the intervals or spans between the tip endsof the adjacent teeth 84 each having wires wound there around. Then, thethree-teeth blocks 87, which constitute a part of the annular orring-shaped iron core assembly, are fixed.

[0207]FIG. 56 shows a circularly coupling process. In this figure, aplurality of three-teeth blocks 87 each having the winding wire andfixed are disposed and combined so as to form a part of a completecircle or ring, and then assembled with each other in such a manner thatthe holes 82 a in the respective first core segment blocks 82 and theholes 83 a in the respective second core segment blocks 83 are alignedin communication with each other in the stacking or laminatingdirection. A pin member 86 is inserted into associated aligned holes 82a, 83 a in the adjacent three-teeth blocks 87 to connect or joint thesethree-teeth blocks 87. The following three-teeth blocks 87 are similarlyconnected with the thus connected body of the blocks. Repeating theabove process, a complete enclosed or ring-shaped core structure isobtained.

[0208]FIG. 57 shows a wire-connecting process, a varnishing process anda shrinkage fitting process. In this figure, with the complete annularcore structure thus formed, the respective windings on the three-teethblocks 87 are connected with each other. Subsequently, a varnishingprocess and a shrinkage fitting process are carried out. Thus, anannular or ring-shaped core assembly 91 for an electric motor has beencompleted.

[0209] In this manner, the first core segment block 82 formed of aplurality of stacked first plate-shaped core segments and the secondcore segment block 83 formed of a plurality of plate-shaped stackedsecond core segments are arrayed and stacked or laminated. Then, a firstcore member comprising a plurality of successively arrayed first coresegment blocks 82 and a second core member comprising a plurality ofsuccessively arrayed second core segment blocks 83 are alternatelydisposed in the stacking or laminating direction in such a manner thatrespective inter-block positions (i.e., clearances or gaps betweenadjacent core segment blocks) of the first core segment blocks 82 aredisplaced or offset from those of the respective second core segmentblocks 83 in the longitudinal direction thereof, with the adjacent edgesof respective core segment blocks adjoining each other in the stackingdirection being overlapped one over another. The edge portions of therespective adjoining core segment blocks are connected mutually bycoupling means 82 a, 83 a, 86. Thereafter, the respective teeth of thecore segment blocks are turned or rotated tooth by tooth around therelated coupling means to form a ring or rectangular shape, thuscompleting an iron core assembly.

[0210] In a medium-sized electric motor such as one according to thethirteenth embodiment, however, the first core member, if formed of amonolithic core segment, would result in a substantial increase in thenumber of component parts and hence resultant complicated structure,thus making it difficult or inefficient to manufacture. In view of this,according to the thirteenth embodiment, a plurality of core segments arestacked and united to form a core segment block so that the total numberof component parts as required can be reduced, thereby improvingproductivity. Moreover, each core segment block is small and compact insize and weight, and simple in configuration and structure, and a firstcore segment block when reversed or turned inside out can be used as asecond core segment block, as a result of which a single common pressingmold can be used for the first and second core segment blocks, and thusthe pressing mold can be minimized in size, simplified in structure andreduced in the manufacturing cost. In addition, if a plurality of coresegments are stacked or laminated to provide three-teeth blocks 87, therespective teeth can readily be turned tooth by tooth around relatedcoupling means with reduced friction, in comparison with the case inwhich monolithic core members are stacked in an alternate manner, asillustrated in FIG. 17.

[0211] It should be understood that in the present invention, the term“enclosed or ring-like” is not limited to “circular”, but insteadincludes “rectangular”, “triangular”, “polygonal” and the like. Thus,the term “enclosed or ring-like” used in the appended claims should beconstrued broadly as including the above-mentioned meanings.

What is claimed is:
 1. An iron core assembly comprising: a first coremember having a plurality of plate-shaped first core segments disposedin succession; a second core member having a plurality of plate-shapedsecond core segments disposed in succession; and coupling means forcoupling edge portions of adjacent core segments of said first andsecond core members; wherein said first and second core members arealternately laminated one over another in such a manner that firstinter-segment positions each defined between adjacent two first coresegments of said first core member are offset from second inter-segmentpositions each defined between adjacent two second core segments of saidsecond core member in a longitudinal direction of said first and secondcore members, with those edge portions of said respective first andsecond core segments which adjoin each other in a laminating directionin which said first and second core members are laminated beingoverlapped each other, and wherein said core segments of said first andsecond core members are rotated relative to each other through saidcoupling means so as to form an enclosed or ring-like configuration. 2.The iron core assembly according to claim 1, wherein said coupling meanscouples together edge portions of those core segments which adjoin eachother in said laminating direction of said first and second coremembers.
 3. The iron core assembly according to claim 2, wherein saidcoupling means comprises: first concave and convex portions respectivelyformed on a front surface and a back surface of each of said first coresegments of said first core member at one end edge portion thereof; andsecond concave and convex portions respectively formed on a frontsurface and a back surface of each of said second core segments of saidsecond core member at the other end edge portion thereof; wherein saidfirst concave and convex portions are engageable with said secondconcave and convex portions thereby to couple said edge portions ofthose core segments which adjoin each other in said laminating directionof said first and second core members.
 4. The iron core assemblyaccording to claim 3, wherein said first concave and convex portions areengageable with said second concave and convex portions throughclearances.
 5. The iron core assembly according to claim 2, wherein saidcoupling means comprises: a first hole formed in one end edge portion ofeach first core segment of said first core member; a second hole in theother end edge portion of each second core segment of said second coremember; and a pin member passing through said first and second holes insaid laminated first and second core segments in said laminatingdirection of said first and second core members in such a manner as toallow relative rotation of said first and second core segments.
 6. Theiron core assembly according to claim 2, wherein each first core segmentof said first core member has one end face at least partially formedinto a convex arc-shaped configuration and the other end face at leastpartially formed into a concave arc-shaped configuration, with theconvex arc-shaped one end face of each first core segment being disposedin abutment with the other concave arc-shaped end face of a first coresegment adjoining in a direction in which said first core segments aredisposed in succession; each second core segment of said second coremember has one end face at least partially formed into a concavearc-shaped configuration and the other end face at least partiallyformed into a convex arc-shaped configuration, with the concavearc-shaped one end face of each second core segment being disposed inabutment with the other convex arc-shaped end face of a second coresegment adjoining in a direction in which said second core segments aredisposed in succession; and a center of rotation of said coupling meanswhich couples the edge portions of mutually adjacent core segments ofthe same core member with each other is-disposed at a location which issubstantially on a bisector for an angle formed by widthwise centerlinesof mutually adjacent two core segments of the same core member and whichis outwardly away from an intersection of said widthwise centerlines. 7.The iron core assembly according to claim 2, where a center of rotationof said coupling means which rotates each core segment is disposed at alocation which is substantially on a bisector for an angle formed bywidthwise centerlines of mutually adjacent two core segments of the samecore member and which is outwardly away from an intersection of saidwidthwise centerlines.
 8. The iron core assembly according to claim 1,wherein said coupling means couples adjacent edge portions ofsuccessively disposed adjacent core segments of the same first or secondcore member with each other.
 9. The iron core assembly according toclaim 8, wherein said coupling means comprises opposing end faces ofmutually adjacent edge portions of successively disposed core segmentsof said first or second core members, said opposing end faces beingformed into an articulated configuration.
 10. The iron core assemblyaccording to claim 1, wherein said first core member and said secondcore member are laminated to form a laminated core unit which hasopposite ends formed into complementary stepped configurations in whichedge portions of mutually opposed core segments at the opposite ends ofsaid laminated are superposed each other in a stepwise fashion in saidlaminating direction.
 11. The iron core assembly according to claim 1,wherein said first core member and said second core member are laminatedto form a laminated core unit which is formed at opposite ends thereofwith a concave portion and a convex portion which are formed on coresegments mutually adjoining each other in said laminating direction andwhich are detachably engageable with each other.
 12. The iron coreassembly according to claim 1, further comprising rotation restrictingmeans provided on opposing end faces of adjacent edge portions ofsuccessively disposed core segments of said first or second core memberfor restricting rotation of said coupling means when said laminatedfirst and second core members are formed into the enclosed or ring-likeconfiguration.
 13. The iron core assembly according to claim 1, furthercomprising reverse-rotation restricting means provided on opposing endfaces of adjacent edge portions of successively disposed core segmentsof said first or second core member for restricting reverse rotation ofsaid coupling means.
 14. An iron core assembly comprising: a first coremember having a plurality of first core segment blocks disposed insuccession, said first core segment blocks each having a plurality ofplate-shaped first core segments laminated one over another; a secondcore member having a plurality of second core segment blocks disposed insuccession, said second core segment blocks each having a plurality ofplate-shaped second core segments laminated one over another; couplingmeans for coupling edge portions of adjacent core segment blocks of saidfirst and second core members; wherein said first and second coremembers are alternately laminated one over another in such a manner thatfirst inter-block positions each defined between adjacent two first coreblocks of said first core member are offset from second inter-segmentpositions each defined between adjacent two second core blocks of saidsecond core member in a longitudinal direction of said first and secondcore members, with those edge portions of said respective first andsecond core blocks which adjoin each other in a laminating direction inwhich said first and second core members are laminated being overlappedeach other, and wherein said core segment blocks of said first andsecond core members are rotated relative to each other through saidcoupling means so as to form an enclosed or ring-like configuration. 15.The iron core assembly according to claim 14, wherein said couplingmeans couples together edge portions of those core segment blocks whichadjoin each other in said laminating direction of said first and secondcore members.
 16. The iron core assembly according to claim 15, whereinsaid coupling means comprises: a first hole formed in one end edgeportion of each first core segment block of said first core member; asecond hole in the other end edge portion of each second core segmentblock of said second core member; and a pin member passing through saidfirst and second holes in said laminated first and second core segmentblocks in said laminating direction of said first and second coremembers in such a manner as to allow relative rotation of said first andsecond core segment blocks.
 17. The iron core assembly according toclaim 15, wherein edge portions of successively disposed core segmentblocks of said first or second core member have opposing end faces oneof which is formed into a convex arc-shaped configuration, and the otherof which is formed into a concave arc-shaped configuration, a convexarc-shaped end face of one of said mutually adjacent core segment blocksbeing disposed in abutment with a concave arc-shaped end face of theother of said mutually adjacent core segment blocks which is adjacentsaid one core segment block of the same core member.
 18. An iron coreassembly comprising: a first laminated core unit; and a second laminatedcore unit; said first laminated core unit comprising: a first coremember having a plurality of plate-shaped first core segments disposedin succession; a second core member having a plurality of plate-shapedsecond core segments disposed in succession; and first coupling meansfor coupling edge portions of adjacent core segments of said first andsecond core members; wherein said first and second core members arealternately laminated one over another in such a manner that firstinter-segment positions each defined between adjacent two first coresegments of said first core member are offset from second inter-segmentpositions each defined between adjacent two second core segments of saidsecond core member in a longitudinal direction of said first and secondcore members, with those edge portions of said respective first andsecond core segments which adjoin each other in a laminating directionin which said first and second core members are laminated beingoverlapped each other; and said second laminated core unit comprising: athird core member having a plurality of plate-shaped third core segmentsdisposed in succession; a fourth core member having a plurality ofplate-shaped fourth core segments disposed in succession; and secondcoupling means for coupling edge portions of adjacent core segments ofsaid third and fourth core members; wherein said third and fourth coremembers are alternately laminated one over another in such a manner thatthird inter-segment positions each defined between adjacent two thirdcore segments of said third core member are offset from fourthinter-segment positions each defined between adjacent two fourth coresegments of said fourth core member in a longitudinal direction of saidthird and fourth core members, with those edge portions of saidrespective third and fourth core segments which adjoin each other in alaminating direction in which said third and fourth core members arelaminated being overlapped each other; and wherein said core segments ofsaid first and second core units are rotated relative to each otherthrough said first and second coupling means so as to form an enclosedor ring-like configuration.
 19. An iron core assembly comprising: afirst laminated core unit which comprises: a first core member having aplurality of plate-shaped first core segments disposed in succession; asecond core member having a plurality of plate-shaped second coresegments disposed in succession; and coupling means for coupling edgeportions of adjacent core segments of said first and second coremembers; wherein said first and second core members are alternatelylaminated one over another in such a manner that first inter-segmentpositions each defined between adjacent two first core segments of saidfirst core member are offset from second inter-segment positions eachdefined between adjacent two second core segments of said second coremember in a longitudinal direction of said first and second coremembers, with those edge portions of said respective first and secondcore segments which adjoin each other in a laminating direction in whichsaid first and second core members are laminated being overlapped eachother; and a second laminated core unit having a plurality ofplate-shaped core segments laminated one over another; wherein said coresegments of said first laminated core unit are rotated relative to eachother through said coupling means thereby to combine said first andsecond core units so as to form an enclosed or ring-like configuration.20. A method for producing an iron core assembly, said method comprisingthe steps of: disposing a plurality of plate-shaped first core segmentsin succession to form first core members; disposing a plurality ofplate-shaped second core segments in succession to form second coremembers; alternately laminating first and second core members one overanother in such a manner that first inter-segment positions each definedbetween adjacent two first core segments of each first core member areoffset from second inter-segment positions each defined between adjacenttwo second core segments of each second core member in a longitudinaldirection of said first and second core members, with those edgeportions of said respective first and second core segments which adjoineach other in a laminating direction in which said first and second coremembers are laminated being overlapped each other; coupling edgeportions of adjacent core segments of said first and second core membersthrough coupling means; and rotating said core segments of said firstand second core members relative to each other through said couplingmeans so as to form an enclosed or ring-like configuration.
 21. A methodfor producing an iron core assembly, said method comprising the stepsof: laminating a plurality of plate-shaped first core segments one overanother to form first core segment blocks; laminating a plurality ofplate-shaped second core segments one over another to form second coresegment blocks; successively disposing said first core segment blocks ina line to provide first core members; successively disposing said secondcore segment blocks in a line to provide second core members;alternately laminating first and second core members one over another ina direction in which said first and second core segments are laminated,in such a manner that first inter-block positions each defined betweenadjacent two first core segment blocks of each first core member areoffset from second inter-block positions each defined between adjacenttwo second core segment blocks of each second core member in alongitudinal direction of said first and second core members, with thoseedge portions of said respective first and second core segments whichadjoin each other in a direction in which said first and second coremembers are laminated being overlapped each other; coupling edgeportions of respective adjacent core segment blocks of said first andsecond core members through coupling means; and rotating said coresegment blocks of said first and second core members relative to eachother through said coupling means so as to form an enclosed or ring-likeconfiguration.